I'd been stuck in Normal mode for a bit longer than expected with these Assassins, due to some failed boss fights at the very end. The heir who had finally made the breakthrough to the next difficulty level was Sir Dude:
Unlike some of my previous Legacy series runs, I had been spacing out the stat purchases between physical damage, health, armor, and critical strike chance. Normally I tend to focus mostly on the first two, and I typically don't invest in critical strike chance until much later on in the game. The Assassin was a bit of a special case here, and I figured that if any class was going to spend some gold on higher crit chance, it was this one. Anyway, I was already up to 43% odds for critical hits, and I would essentially deal triple damage any time that I rolled one of them. That would be enough to one shot many of the low health monsters in the early portions of New Game Plus. My equipment was about average for this point in time in the game, and I hoped to upgrade with the superior stuff that drops in higher difficulties. One thing that was nice: I had 49/55 runes at this point, by far the most ever for me entering NG+ mode. The Assassin's innate ability to pick up all of the "take no damage" fairy chests, along with my growing player skill at this game, had combined for a truly impressive result in that regard. I guess that was the one advantage from being stuck full clearing Normal difficulty repeatedly, grabbing a ridiculous number of runes.
Unlock: Attack Up x6, Health Up x4, Armor Up x4, Equip Up x2, Guardian Chestplate
All of the leftover gold from the final Normal run went into general stat bonuses, and equipping the Guardian Chesplate that I found inside the hidden Calypso's Compass room. I figured that New Game Plus difficulty wouldn't be that tough, since the Assassin is inherently a strong class and my character was a bit overleveled. Time to venture back inside the dungeon and find out.
13) Level 128 (Health 34, Attack 21, Armor 15, Equip 21, Crit Chance 12, Crit Damage 1, Mana 2, Gold Gain 5, Potion 5, Miscellaneous 12): 95,471g
It was great to be running the dungeon in NG+ mode again, where everything was a lot more interesting and challenging. Most of the enemies died very quickly when I landed a critical hit (43% chance), and took significantly longer when I did not. It was 78 damage against 230 damage, a big difference. The equipment in treasure chests was a lot better on this difficulty level, as I found the Dragon Sword and Imperial Helm almost immediately in the castle. I cleared that whole area out without too much fuss, and then ventured into the forest. There were several rooms full of bouncing spiked balls in there, where I was able to pick up even more runes inside fairy chests. I also found the Royal Chestplate, in my opinion the best chestplate armor in the game. After finishing up with the forest, I went into the tower, where the most interesting room was a fairy chest "defeat all enemies" challenge with Chaintus (ball and chain) monsters everywhere. There was no way to prevent the room from filling up with bouncing spiked balls everywhere once again, kind of a recurring theme for this Assassin run. I managed to clear out the tower as well, with one retreat at low health to restock on chickens when I fell down to 40 HP. Found the Slayer Bracers in there, the bonus crit chance making them particularly attractive for an Assassin run. Then it was down into the basement, right away on my first NG+ character, where I found more useful gear in the form of the Dragon Helm. That one is almost as good as the Royal Helm, just a bit short on stats, best I had by a good margin. Then the Royal Helm itself dropped outside the basement boss door - sorry, Dragon Helm! You've been outclassed. Eventually the basement was clear as well: complete full dungeon run with my first character in NG+ mode, only the bosses remaining. That was a bit unexpected, but only a little bit. My Assassin was overleveled from being stuck in Normal difficulty for so long, and the Assassin as a class is pretty darn strong.
Against Khidr, I played a thoroughly terrible battle, taking three hits in a mere four attack cycles from the boss. I simply did an awful job of dodging his shots, not much more to say. Very poor play. That meant that I didn't quite have full health against Alexander, and even though I played pretty decently in this battle, he eventually overwhelmed me with swarms of the flying skull heads. I think I needed more damage there, to get through Alexander's lifebar before he could spawn more of his minions. In any case, certainly a pretty slick run that clocked in at just over 95k gold. I had also brought back tons of awesome new equipment, as well as the final six runes. I actually opened eight fairy chests, getting those last six runes and then two stat bonuses (health and magic damage). Apparently I've gotten pretty good at fulfilling the fairy chest challenges. I needed 10 equipment points to put on all of the new gear, and then that left 55k gold remaining for some nice stat upgrades, 28 levels in all by the time I was done.
Unlock: Health Up x11, Equip Up x10, Crit Chance Up x4, Armor Up x2, Mana Up, Dragon Sword, Royal Helm, Royal Chestplate, Slayer Limbs
14) Level 156 (Health 45, Attack 21, Armor 17, Equip 31, Crit Chance 16, Crit Damage 1, Mana 3, Gold Gain 5, Potion 5, Miscellaneous 12): 105,143g
Tunnel Vision. All of those stat points and new equipment added up to a much stronger Assassin compared to my previous ancestor. I was all the way up to 499 starting health, up from 375 HP on the last guy! I went through the castle first, just to find all of the teleporters in case I had to retreat back for more health and mana later. It turned out that there were a bunch more fairy chests in the castle, and I picked up three of them in the first five minutes of play. More free stat bonuses! I went into the tower, took some damage there, retreated to the forest to restore life, and wound up clearing the whole thing without ever hitting full health again. I actually did better when I went back into the tower, for whatever reason I took less damage there. This was a character that I was never really satisfied with playing, as I always seemed to be sitting around half health, never on full. (Then in the final room of the tower, when I did have full life, the room randomly dropped three chickens that I didn't need. Typical.) I went through the basement as well, and picked up a full dungeon clear, just like the previous Assassin. That left only the bosses yet to be completed.
Alexander was no trouble at all this time. The extra health and damage made him a cinch, and I was barely scratched in this fight. Ponce de Leon was significantly tougher, I kept getting hitting by the bouncing spiked balls in his chamber. I'm convinced that they get placed in different spots each time that you do the fight, as sometimes they never hit me and other times I'm getting smacked around repeatedly. The retaliation damage on my Slayer Bracers killed the spiked balls each time they hit me, and that did make a difference in the fight. I won with about 200 health remaining. The victory chest produced a triple health upgrade, something I've never seen before! The stat bonuses in there appear to be completely random, so getting three of the same stat isn't impossible, just rare. It made for an interesting picture. Then I had no choice but to fight Herodotus, and although I put up a valiant fight, I wasn't able to win with such low starting health. With anywhere near full HP I would have won with ease. Hopefully one more Assassin needed to finish New Game Plus difficulty. There was no new equipment worth grabbing at the Blacksmith, the new gear that I found being inferior to what I already had. That meant a lot of money sitting around for stat upgrades, 27 more levels in total.
Unlock: Attack Up x11, Health Up x10, Armor Up x4, Crit Chance Up x2
15) Level 183 (Health 55, Attack 32, Armor 21, Equip 31, Crit Chance 18, Crit Damage 1, Mana 3, Gold Gain 5, Potion 5, Miscellaneous 12): 145,225g
Dwarfism, I had a tiny character model this time. While I like the ability to grab the treasure chests that are normally out of reach with the dwarf characters, I actually think that they aren't great for fighting bosses, because their sword has such a tiny hit box. We would see how this guy fared. As it turned out, I was laughably bad at playing this character out of the gate. Starting in the easy castle region, I was absolutely god-awful. The lowlight came in a routine room with spikes on the bottom, where I managed to jump into the spikes no less than THREE TIMES for zero reason whatsoever. 
I was down to about 150 health (out of a lifebar that maxed out at 596 HP!) and I was trying to figure out what in the world was going on. I guess it was rustiness or perhaps a random streak of terrible play, because I settled in and slowly managed to rebuild my health, although it took the full castle before I was back near full again. Weird. The dwarf character was kind of funny to play out, in particular one room early on where I came across a Gradiator. Pictured above, I felt as though I was hacking at the shins of the gigantic black knight. THIS was the hero that was going to save everyone?! It was pretty comical.
Terrible opening run of play aside, this Assassin was honestly too strong for the dungeon to pose much of a challenge. I had little trouble clearing my way through all four regions of the map. When I found the boss door in the basement, I had full health, and I went inside immediately to face Herodotus. Since I almost won the battle with a mere 200 health on the last attempt, and with lower stats and weaker gear, you can imagine that I had very few difficulties emerging victorious on this playthrough. Yes, it could have been done better, but I was never in any danger at all, and still had over 400 health at the end of the fight. Because I was under such low pressure on this run, I was able to fight the duo plant miniboss in both the forest and the tower, a miniboss that I typically skip. I think that I'm starting to get their pattern down too: the trick is to fight them from the ground underneath them, not on the upper platform next to them, as I had been trying before. With my success against Sallos on an earlier Assassin, I might be getting close to having the pattern down for every miniboss. Still need some more experimenting though.
The final two bosses were fairly anticlimatic this time around. I often find them to be easier in NG+ and NG++ than in Normal difficulty, since they don't seem to scale as hard as your character does with more levels and more gear. I dodged the Johannes spells as best I could, and I seemed to be doing better at predicting when he would use his melee sword attack. There's a pattern there, naturally, I simply have to get better at reading it. The Fountain was a matter of playing patiently, waiting to dodge his various projectiles (using the smoke cloud as needed) and attacking when I had a clear shot. His ground attack is the easiest time to get damage, since you can bounce on his head repeatedly and get free hits in. The Fountain hit me three times in rapid succession when I screwed up badly, and otherwise never touched me at all. I had about half my life remaining when he kicked the bucket. On to NG++ mode.
According to those end game screenshots, I had spent four heirs and less than four hours in NG+ difficulty, and even that overstated things since it included the non-Assassins that I had to kill off. All three of my characters had full cleared the dungeon, and both deaths had taken place against bosses. I knew that things were going to be harder in NG++ mode, and I was eager to see how I would fare.
Unlock: Attack Up x12, Health Up x11, Crit Chance Up x7 (maxed)
There was no new gear worth purchasing from the Blacksmith. I had found quite a bit of Holy and Slayer equipment on the last run, but none of it was better than what I currently had. Even for an Assassin, I preferred the Royal Helm and Royal Chestplate over their Slayer counterparts. When it came to upgrades, I first maxed out critical strike chance, taking me up to an amazing 73%. (The max possible is 85% on an Assassin, and 70% on all other classes.) Then I divided the rest between health and attack upgrades. By the time I was finished, I had nearly a dozen of both, and 30 total levels added to my character. I hoped that would be enough to let me survive the upcoming challenges of NG++ difficulty.
15) Level 213 (Health 66, Attack 44, Armor 21, Equip 31, Crit Chance 25, Crit Damage 1, Mana 3, Gold Gain 5, Potion 5, Miscellaneous 12): 4050g
This character's venture into the new difficulty was a complete and utter disaster. I took way too much damage in the second room, which had McRibs inside little enclosed platforms where I couldn't reach them, and then the third room was even worse. I misplayed the situation horribly and took way too much damage. I had the same problem as my NG+ run, where the tiny sword caused me to keep jumping into enemies when I swung at them with my sword. In any case, it was over almost immediately with a pathetic 4k gold run. Whoops. Not the run I envisioned to start!
Unlock: Crit Damage Up
16) Level 214 (Health 66, Attack 44, Armor 21, Equip 31, Crit Chance 25, Crit Damage 2, Mana 3, Gold Gain 5, Potion 5, Miscellaneous 12): 51,824g
IBS trait, your character farts a lot. I had to hope that this Assassin would do better. While I did clear that very low bar, I wasn't especially pleased with this Assassin either. I managed a full clear of the castle, and made it through maybe a quarter of the forest before dying to the Chaintus ball-and-chain monsters. My struggles here may have been partly due to getting acquainted once again with the challenges of NG++ difficulty. It's such a massive step up in difficulty level, and I had quite frankly been coddled by the previous modes of play. I needed to be sharper with my use of the smoke cloud to dodge hits, and better at the tactical play of fighting the monsters. I was taking too many sloppy and unnecessary hits. The almost complete lack of chicken drops for this Assassin certainly hadn't helped either. Anyway, I used the resulting gold to max out health and drop a final point into damage.
Unlock: Health Up x9 (maxed), Attack Up
17) Level 224 (Health 75, Attack 45, Armor 21, Equip 31, Crit Chance 25, Crit Damage 2, Mana 3, Gold Gain 5, Potion 5, Miscellaneous 12): 57,202g
OCD and Nostalgic traits; the free mana from breaking stuff was nice, the sepia colored screen not so much. With maxed health upgrades, I started the dungeon at 746 HP, and I'd need to find health bonuses in fairy chests or from defeating bosses to get any more additions. The beginning of this run went well enough; I killed the duo flying mages without trouble, and even managed to clear out a "defeat all enemies" fairy chest room without taking a hit. However, I ran into trouble in a very small room that had two Gradiators and a flying mage inside. There wasn't much room to manuever in there, and I messed up badly, using the smoke cloud at the wrong moments and taking two hits from the Gradiators in the process. Each one did 192 damage, OUCH!!! 
Along with a hit from the mage, this took me from full health down to almost zero. Although I did manage to clear most of the castle, this one room crippled my run and prevented me from making further big gains. Watching it again when I went back to take a screenshot, I found myself wishing (as usual) that I had used the smoke cloud better. I could have dodged a good amount of damage with smarter play on my end. I'd have to keep working on this, as I clearly still needed more practice. The unlocks were obvious: dump everything into attack damage, and anything left over into armor.
Unlock: Attack Up x8, Armor Up
18) Level 233 (Health 75, Attack 53, Armor 22, Equip 31, Crit Chance 25, Crit Damage 2, Mana 3, Gold Gain 5, Potion 5, Miscellaneous 12): 124,060g
Coprolalia and Gay traits, neither one affecting gameplay at all. This was a brutally difficult run, easily up there amongst the hardest I can recall. The first couple rooms weren't that bad, but then it started throwing out some ridiculous setups. The first such room had two McRibs on a center platform, surrounded by four cannons, two mages, two corrupt lords, and two zombies. I fell down under 200 health clearing that out, then the next room had four more McRibs, four Plonkies, and a scattering of zombies and corrupt lords. I had a mere 113 HP remaining at that point, and this run surely seemed doomed to an early defeat. I actually staggered through another extremely difficult vertical room full of eyeballs and fake paintings, dropping as low as 50 health in the process, then afterwards began to find some teleporter rooms and raid their chickens. This gave me a lifeline, and along with some very patient and careful play allowed me to make something of this run. After that, I went through a small room with two McRibs and two zombies, then a room with a pair of flying Infernites and a quartet of mages, followed by another large open room with two McRibs, four fire mages, two Plonkies, and two paintings. Then the next room had four eyeballs and two ice mages in a small space, with the last room behind that containing even more McRibs with traps raining down fire from the sky. And all of that was in the first half of the castle! It was a minor miracle that I managed a full clear of the castle. I chose to go into the tower from there, and found it to be noticeably easier, since the McRib skeletons can't spawn up there. I made it through nearly all of the tower, leaving just one room that was particularly obnoxious to handle, with an unreachable eyeball behind a wall spewing endless red goo. Not interested, sorry. I had very little health left at this point, and only made it two rooms into the forest before falling, with a Tower Guard (shield enemy) throwing me onto a spike trap as I delivered the killing blow. Sheesh! Well at least I got him too. I went ahead and uploaded this recording to YouTube, since it had been one of the more memorable runs that I had done in a long time.
Unlock: Attack Up x16
19) Level 249 (Health 75, Attack 69, Armor 22, Equip 31, Crit Chance 25, Crit Damage 2, Mana 3, Gold Gain 5, Potion 5, Miscellaneous 12): 19,427g
Hypergonadism (super knock back) and Alzheimer's (can't access the map screen). I had turned my 120k gold from the last character into 16 attack upgrades, and the difference was very noticeable with this Assassin. Now my base attacks did 160 damage and critical hits did 504 damage. Two crits would kill just about any monster that I came across. Unfortunately, this run was even more packed with McRibs than the last one, as I faced eight of them in the first three rooms. I didn't get a single chicken drop, and the endless rain of bones was my undoing. The super knock back is actually really bad against McRibs, since they go flying away from you and it makes it much harder to burst them down quickly. Disappointing character run.
Unlock: Attack Up x2
20) Level 251 (Health 75, Attack 71, Armor 22, Equip 31, Crit Chance 25, Crit Damage 2, Mana 3, Gold Gain 5, Potion 5, Miscellaneous 12): 203,279g
Eid. Memory on this Assassin. I hoped for better than my previous heir, and fortunately that proved to be the case. I rolled a vastly easier draw in the castle compared to my past two Assassins, with only a sprinkling of the McRib skeletons here and there. Honestly, I was barely even challenged making it through the first part of the game, and achieved a full clear in the castle without any trouble. Along the way, I fought the duo skeleton miniboss and picked up the Dark Helm as a reward, then later fought Botis and found the Dark Chestplate. Those were both very nice indeed, although I do prefer the Royal Chestplate because of the huge armor penalty on the Dark version. Once again, I went into the tower after the castle, and that area was significantly tougher. I drew a lot of difficult room layouts, and eventually I had to retreat out of there to pick up the chickens at the teleporter rooms. One really irritating thing about this was a vertical fire-shooting trap in the first room of the tower, which I had to use the smoke cloud to pass through every time I entered or left the tower. Instead of finishing that area, I headed into the forest, which proved to be quite difficult as well. There were a lot of McRibs in here again, and I was constantly on the verge of dying, seemingly in the 100-300 health range all the time. I did eventually get all of the way through the forest, and then returned to the tower once again to complete the rest of that region. I made it to the final room of the tower, which was a "defeat all enemies" fairy chest challenge, having a mere 180 health left. I was pretty certain that this room was going to kill me, but I tried to get through it anyway. Of course, it did kill me when I took two hits from the masses of grouped enemies. Overall though, I was pretty happy with this character's journey, as he picked up just over 200,000 gold and essentially full cleared three of the four areas of the dungeon.
With all of the gold, I went ahead and picked up some utility upgrades. First I dumped in the last four points to max attack damage, then unlocked my way over to Randomize Children and dropped the five points into Invuln Time Up. That's a very useful ability, it's just so expensive to pick up until very late in the game. After that, I decided that I would maximize critical strike damage over armor, and picked up a full 21 points into that skill, leaving me at 23/25 with just two upgrades left to go. Next time, I would finish off that skill and start pumping armor, and that would pretty much be it for Assassin upgrades.
Unlock: Attack Up x4 (maxed), Crit Damage Up x21, Invuln Time Up x5 (maxed), Equip Up x4, Unlock Spell Thief, Upgrade Spell Thief, Mana Cost Down, Randomize Children, Slayer Cape
21) Level 289 (Health 75, Attack 75, Armor 22, Equip 35, Crit Chance 25, Crit Damage 23, Mana 3, Gold Gain 5, Potion 5, Invuln Time 5, Miscellaneous 16): 161,796g
Dwarfism and EDS, another tiny Assassin. I've never really liked the dwarf trait, largely because your sword's hit box becomes diminishingly small, making it difficult to hit a lot of targets without taking hits in return. You do get some funny pictures sometimes, like above where I was hiding out in the floor underneath a massive Gradiator. In any case, this particular Assassin drew a much easier castle section compared to the previous two heirs, and I was able to make my way through with minimal trouble. My three points of vampirism (+6 health per monster kill) were actually keeping up with damage taken, and I didn't have to raid all of the teleporter chickens the moment I found them. There was only one really tough room: two eyeballs, two corrupt lords, two paintings, an ice mage, and a bouncing spiked ball, all in a single very small room. The smart thing to do would have been to skip it, but instead I waded through, soaked in blood, at the cost of half my health bar. I picked up Hedgehog's Curse from a secret shrine along the way, then was able to drop it in favor of Hyperion's Orb later on at another secret shrine. I really hate the Hedgehog one, and how it makes you lose gold upon taking damage, even if it makes for cool screenshots:
The forest wasn't too bad, although more McRib skeletons still made my life miserable at times. I found myself having to watch my mana consumption, as I would run too low at times from frequent employment of the smoke cloud. Bad rooms made the mist form a necessity, and yet the low mana pool of the Assassin had me carefully weighing how and when to dip into those magic point resources. It would have been even worse had I not gotten so many Mana Up crystals out of fairy chests, probably close to a dozen by this point in time, which was kind of a mixed blessing. I really would have preferred more health or damage! Anyway, bad room draws and some misplays on my part had me raiding many of my saved resources by the time that the forest was finished. I actually died in the tower against a pair of wolves, only to roll a Death Defy at minimal odds and come back to life! This allowed me to clear more rooms, pick up a lot more gold, and even defeat two minibosses in the tower, both Botis and the duo flying mages. They produced the Dark Cape and the Dark Bracers respectively, the latter of which was a real upgrade. (I took a hit right at the start of the mages fight, and then did the rest of the battle on 22 HP without dying. No desire to test another Death Defy!) In the end, I cleared out pretty much the entire tower, and fell in the final room, which was another "defeat all enemies" fairy chest challenge. I had just over 100 health, and was almost certain that the room would kill me, but hey, why not. It did indeed kill me, so no YOLO SWAG this time. I had been fortunate to get a second life to begin with.
I went ahead and purchased the Dark Limbs (replacing the Slayer Limbs), trading some crit chance and crit damage for an extra point of vampirism, siphon, and another air jump. All of those stats were useful, even the extra air jump, which I've found to be very helpful against certain NG++ enemies. I left the Slayer Cape in place over the Dark Cape though, since I didn't need a second point of Siphon or a fourth air jump. Then I put the rest of the money into the last two crit damage upgrades, and a ton of armor upgrades, 19 in total, which nearly maxed out that stat. That took me up to 288 armor (59% damage reduction), and along with slightly more vampirism, I hoped that it would make sustaining through long runs that much easier.
Unlock: Crit Damage Up x2 (maxed), Armor Up x19, Equip Up x4, Mana Up, Dark Limbs
22) Level 315 (Health 75, Attack 75, Armor 41, Equip 39, Crit Chance 25, Crit Damage 25, Mana 4, Gold Gain 5, Potion 5, Invuln Time 5, Miscellaneous 16): 337,574g
Baldness and Dementia. The insanity from the Dementia trait is a lot easier to deal with here in NG++ difficulty, since all of the fake monsters are the non-upgraded tier one enemies. They tend to stand out a bit! Once I made it inside the dungeon, I found that the increased armor and extra point of vampirism seemed to have pushed me across some kind of tipping point. I had little difficulty making it through each section of the dungeon, never falling much below half health and failing to hit any true danger moments on a smooth path to a full clear. I even managed to find Calypso's Compass from a secret shrine in the basement; the hidden room produced the Royal Sword and the Dragon Cape, both pieces of gear that I sorely wished I had found earlier! I was still using the severely outdated Dragon Sword for lack of better choices. Along with the Black Sword, which Botis dropped in the forest on this run, I had now found every single piece of equipment. (Thankfully, I'm running the GOG version of Rogue Legacy and don't have to deal with those silly Steam achievements popping up.) One of the highlights of this character was an absurd run on Mana Up crystals located in fairy chests; I began the run with 198 magic points, and had 224 magic points by the end, a full increase of 26 MP. But even that understated things, since the Assassin has a base mana stat of 60% compared to the Paladin, which means that I actually picked up a full 8 Mana Up crystals during the course of this run. Eight of them! 
That included a double dose of mana crystals from Alexander:
Speaking of bosses, this Assassin cleared out all four of the dungeon's major bosses, along with a couple of minibosses along the way. I had cleared the castle and forest first, and then went into the chambers to face the first two bosses. Khidr failed to hit me even one time, although I did use the smoke cloud to dodge some projectiles. That almost felt like cheating, given how easy he is to defeat. Alexander put up slightly more of a fight, hitting me one time. He still died when I had 705 HP out of 753 HP remaining, it wasn't exactly close, and then dropped those mana crystals pictured above. Unlike the first two bosses, I fought both Ponce de Leon and Heredotus as I came across their boss doors, and executed very well against both of them. Ponce didn't hit me even once, and I walked out of there with one of my few flawless Ponce victories. (And yet ANOTHER mana crystal!) Heredotus was a bit more sloppy, but with four points of vampirism for +8 health per blob kill, there wasn't too much that he could do. I was actually killing the flying earth mages in a single hit when they popped out, as critical strikes were dealing over 700 damage apiece. Many of the lower health monsters elsewhere in the dungeon would die from a single crit as well, things like the eyeballs and wolves. Pretty much everything would die in two crits, this being only NG++ and not higher in terms of monster health. Almost before I knew it, the dungeon had come to a close, and I had a full clear of everything along with some 300,000 gold in pocket.
The Johannes fight was almost laughably easy due to RNG (random number generator) reasons. The room in which the final battle takes place has eight breakable objects in it, the same sort of junk that you find everywhere throughout the dungeon. They have the normal chance to drop gold, recovery items, or nothing. Normally they don't produce anything out of the ordinary, but on this particular occasion, there were THREE chickens inside those destructable objects, and that wasn't counting the four additional chickens that always appear after defeating Johannes. Given a full SEVEN chickens to do this two-part fight, I certainly wasn't going to come up short. I killed the Fountain with full health and full mana. Piece of cake. (These last two bosses are genuinely more difficult in Normal difficulty than NG++ difficulty. They don't scale up nearly as well as your character does when given roughly 200 more levels worth of stats.)
That was all she wrote for NG++ difficulty with my band of Assassins. It took me 22 total characters to complete New Game Plus Plus, and only 8 Assassins to finish up NG++ itself. If I hadn't thrown away two Assassin heirs in fairly useless fashion, it could have been even better. The concluding 337k gold run was also a personal best for NG++ difficulty, none of my other characters have managed to hit that mark without reaching NG+3 or higher. The Assassin took slightly more heirs to finish off the three dot run compared to the Barbarian (which completed the journey on character #17), but the Assassin as a class is probably stronger in extreme lategame once you do reach that point. In other words, the Barbarian has an easier path to the end of NG++ mode, while the Assassin is better with everything maxed out. If all you're doing is using the Architect to run bosses endlessly, the Assassin is clearly the best choice. I think the two classes are fairly comparable in overall strength, with the Barbarian more geared to defense and the Assassin more geared towards offense. I don't consider anything beyond NG++ to be a true part of the game anyway, since the dungeon itself stops changing. Take your pick between the classes, it's a personal preference.
Given the success of this particular character, I decided to keep going into NG+3 difficulty level. I used the massive amount of gold from the previous run to unlock the Royal Sword and Vampire Cape, which added an extra 20 physical damage and two more points of Vampirism (now +12 HP per monster kill with six total vampirism points). I've heard that you get more health back in the higher difficulties with the most recent patch, but I'm holding off on downloading that until completing the Legacy series so that I can make more accurate comparisons between classes. The rest of the gold then turned into 61 additional levels, used to finish maxing out the armor stat and then start loading up on Mana Up upgrades. I think I made it to roughly 50/75 on the mana stat before running out of gold. This took me over 500 MP, and finally gave me a healthy mana pool to use for the Assassin's smoke cloud. I could now take off the restraints I had been using thus far and run the mist form almost indefinitely.
With the extra damage, more mana, and extra vampirism for sustain, I found NG+3 to be relatively easy. My Assassin breezed through a full dungeon clear, all bosses slain, more than 500k gold earned in pocket:
I hadn't truly been threatened at any point on that run, and had even managed to pick up some more fairy chests for stat gains along the way. I went ahead and spent the new haul of gold on further upgrades at the castle tree, this time 76 more levels in all, taking me up to Level 452. I finished maxing out the mana stat, winding up with just over 700 max MP after spending nearly the entire Assassin run with less than 200 MP. The rest went into stats that were pretty much useless for this character, like the magic damage (Intelligence) stat, but what else was I going to purchase with all that gold? I had to spend it on something. Eventually it was all gone, and I was back down to ~1000 gold, heading back into the dungeon again. I kept the same equipment, using my preferred endgame setup of Royal Sword, Royal Helmet, Royal Chestplate, Dark Limbs, and Vampire Cape.
The NG+4 dungeon was noticeably harder than the previous difficulty level. I had to work hard to make my way through this one, using the smoke cloud nonstop to minimize the damage taken. Still, I did well enough to avoid raiding the teleporter chickens, and even had enough health to fight a series of minibosses that dropped further gold along the way. I also found Hyperion's Ring along the way in a secret shrine, although I didn't think too much about it. Once again, I was able to full clear the entire dungeon, defeat all four bosses, and ultimately take down Johannes and the Fountain, earning 836k gold in the process:
This was the highest gold total that I had ever brought back by a fairly wide margin. I now had a complete run through NG+4 difficulty level, the highest point that I had been able to achieve with the Barbarian earlier. Did I dare to try one rank even higher, the NG+++++ (NG+5) difficulty mode? Why not, right? Might as well. This time I bought all of the remaining levels in the castle, up to Level 503, leaving just four unspent points in the "Haggle" skill because I wanted my gold to drop down to zero when I entered the dungeon again. (Level 507 is the maximum possible in this game.) That still left me with hundreds of thousands of unspent gold, so I purchased all of the equipment from the Blacksmith and all of the runes from the Enchantress. (Then I rearranged my runes to make them look slightly more neat in the bottom left corner of the screen. Might as well be fashionable!) This finally dropped me down to zero gold again, allowing me to get a fresh total for this last attempt.
The NG+5 dungeon was brually difficult, even for an Assassin. Keep in mind that my stats had barely increased, at least not in the crucial categories like health and physical damage, while the monsters had been scaled up from NG++ all the way to NG+5 difficulty. The average enemy now had 1500 to 2000 health, and despite my 340 armor (63% damage reduction), they would deal almost 200 damage per hit taken. I still had just over 800 HP, which didn't leave much room for error. I was aided in my attempt at a full clear by some good fortune, as I ended up finding two fountains along the way for health and mana refills. They were needed very badly, including the mana refill part, as I was burning through MP at a crazy rate as I kept needing to duck into the smoke cloud. I even tossed a few chakram from time to time as the situation dictated. I fought the bosses whenever I found a boss door and had full health, which worked pretty well for the first three bosses but nearly got me killed against Herodotus. I was actually a single hit away from death towards the end of that battle, and I managed to kill the final six or seven blobs without taking that final hit. Tense, nerve-wracking stuff.
I did manage the full dungeon clear, but only by the skin of my teeth. I'd also been forced to eat all of my teleporter chickens along the way, and drink from both of the fountains, which meant that I had to go into the Johannes and Fountain battles with less than full health. I think that I was sitting at roughly 500/800 HP or something along those lines. The entryway to the final boss fight from the game's demo did not drop any chickens either, which was a spot of poor luck after all the times that I've gone through there on full life and gotten a chicken that I didn't need. Anyway, I wasn't too worried about the Fountain, whose pattern I've gotten down fairly well by this point, but I worried greatly about Johannes. Fighting him on less than full health was going to be tough, very tough. We had a brilliant fight, both of us gashing the other repeatedly, until we reached a point where both of us were on one hit. I knew whoever hit the other first was going to get the kill. And right there, with everything on the line, as we charged at each other for the final blow... Johannes hit me first.
But wait! There was one thing that I'd totally forgotten: I had Hyperion's Ring in my inventory, picked up on the previous difficulty level and still sitting there because this was the same Assassin. Hyperion's Ring grants your character one free Death Defy, reviving you with 25% health. I had completely and utterly forgotten about this. Suddenly I had a second chance! I slapped Johannes with my sword, he did indeed die from one additional hit, and then I grabbed the four chickens that dropped. There was no way that the Fountain was going to defeat me, not after all that I'd been through, and frankly I kicked his ass and sent him home crying to mommy. 
NG+5 full cleared as well, from start to finish, with the same Assassin:
I was a little bit disappointed that this run only produced slightly more gold than the one from the previous difficulty, despite the extra gold bonus that you receive for every additional level of New Game Plus. It points to the randomness of each particular run. I was on the high end with my NG+4 run, finding a lot of chests and fighting several minibosses, while the NG+5 run was on the low end in both areas. In fact, the entire tower area had a mere five treasure chests with gold inside (despite lots of difficult monster fights), which is among the fewest I've ever seen. I've found close to triple that sometimes. In any case, I'd have to live with a mere 884,673 gold for my current high score on a run. Still hoping for a million at some point!
Sir Gouda became the finest individual character that I've ever played. He obtained a full dungeon clear of NG++ difficulty, then NG+3, then NG+4, and then NG+5. No use of the Architect, all rooms cleared, all monsters slain, all bosses defeated. Adding those four runs together produces a grand total of 2,587,275 gold earned, which is nothing short of incredible. I retired the character at this point without ever having ventured into NG+6 difficulty, not wanting to lose him. Sir Gouda the Invincible will live on forever, never having been defeated by the dungeon. The Assassin Who Lived! 
There's the final screen after defeating NG+5 difficulty, the exact same number of heirs used, an additional four and a half hours of time on the clock. These last couple of runs truly exceeded my wildest expectations for the Assassin class. I'm not sure that I could have pulled this off with any other class, at least not without needing a couple of tries. To get everything right the first time and full clear four straight difficulty levels without dying... well, it's more than I ever expected to see. I'm honestly not sure that I'll be able to top this in terms of player achievement, so in a way it's almost a bit sad, getting closer towards the end of what I hoped to achieve with Rogue Legacy. Still a ways to go though before hitting that point, I need to finis the Legacy series and then there's at least one more idea I want to try after that.
As always, thanks for reading. Best of luck to all of you if you ever try to replicate Sir Gouda's quest.
