I made it through the Normal difficulty with a mere 11 Barbarian characters. Just missed my personal hope of doing it with the tenth fellow! In any case, Sir Culp now continued his quest in New Game Plus mode with the following stats:
My upgrade points had gone rather heavily into health and physical damage, typical for a melee brawler like the Barbarian class. I was lucky that I could avoid having to sink 50k gold into Mana Cost Down upgrades like my Archmages, and could go straight for raw stat gains. My equipment was mostly comprised of Ranger and Guardian stuff, along with the recent find of the Imperial Helm. My runes were very basic as well: three points of Vampirism (for +6 HP per kill) along with the default dash and double jump. Nice and simple, just like the Barbarian. I still had 48k gold saved up from the final Normal clear of the dungeon, which immediately went into the following levels:
Unlock: Health Up x6, Attack Up x6, Armor Up x6
11) Level 119 (Health 25, Attack 30, Armor 16, Equip 21, Mana 4, Gold Gain 5, Potion 5, Crit Chance 1, Crit Damage 1, Miscellaneous 11): 83,079g
I resumed play with the victorious Barbarian from Normal difficulty, Sir Culp. Unfortunately this meant that I had another long playthrough to do with the Alzheimer's trait and no access to the map, argh. I found that most enemies in the castle took three or four hits to defeat, which is about what I expected. With 600 health to play around with, and each chicken drop restoring 100 HP, I wasn't in any serious danger in these areas. I found the Dragon Bracers in one of the early chests, and that's an equipment set that won't appear until you reach NG+ mode. The Dragon stuff is all quite good, just a little weaker than the Royal gear. I full cleared the castle and headed into the forest, where I picked up the Sky Sword and the Royal Chestplate. That was a major gain, all of the Royal stuff is exceptional. After clearing out the forest as well, I decided I might as well fight Khidr for fun. This was almost too easy, since I could use the Barbarian shout to brush away any of his projectiles; I got a great picture of the shout in action above. Even so, I played the battle rather poorly and took quite a few hits. I mean, it did take a long time to whittle away at his 4444 health at 83 damage per swing. Still, the danger factor was almost nonexistant, and I walked away the victor with well over 300 health still remaining. Rewards were strength, magic damage, and mana increases. For some reason, I kept getting mana crystals as bonuses on every boss, heh. From here I went into the tower, where I found the Royal Helm and Royal Bracers almost immediately. More top tier gear showing up. I wouldn't even need to search for much more equipment, given all the Royal stuff appearing.
At this point, I had no choice but to go down into the basement, where I continued to make excellent progress forward. I fought Botis down there and beat him without taking a scratch - I've really learned his pattern cold at this point. Reward was the Holy Cape, probably not useful for a Barbarian. Then I found the Slayer Helm down in the darkness, which might be even better than the Royal Helm for a character like this. I made it through well over half the basement before finally dying, and I would have made it further than that if I hadn't had a brainfart and played one room horribly. Over 83k gold and a ton of new equipment from the very first run. I clearly wasn't going to be in NG+ difficulty for very long. I cleared out 80% of the dungeon on the very first NG+ character - where was the challenge?! 
Roughly half of that gold went into using the new gear... that and the ELEVEN equipment upgrades that I needed to put them on. Sheesh. My formerly colorful attire had been largely replaced by the drab grey colors of the Royal Helm, Chestplate, and Limbs. At least I still had a bright blue sword and a green cape to add some pizzazz. The rest went into more stats, particularly more damage.
Unlock: Sky Sword, Royal Helm, Royal Chestplate, Royal Limbs, Equip Up x11, Attack Up x9, Health Up, Crit Chance Up
12) Level 141 (Health 26, Attack 39, Armor 16, Equip 32, Mana 4, Gold Gain 5, Potion 5, Crit Chance 2, Crit Damage 1, Miscellaneous 11): 83,377g
Gigantism, Eid. Memory. I had a very big, very blue sword. Maybe it was due to the big character model from Gigantism trait, but this was a run that I was never satisfied with while playing, even though I managed to make some good progress. I turned up the Imperial Sword (along with a whole bunch of other outdated gear that was inferior to the Royal stuff) as well as a good number of runes. Cleared out the castle, forest, and tower, at which time I went into the forest boss door to face Alexander. That battle went pretty well, and I discovered that the Barbarian shout would knock away both the little flying head shots and Alexander's giant purple beams of death. For whatever reason, I had thought that the shout would only clear the little ones. This made the battle fairly easy, even if it took a while to cut through all that health. From there, I went after Ponce de Leon in the tower, and this was a battle that was poorly fought on my end. I had plenty of MP to clear out the flame projectiles, but for whatever reason I took hit after hit after hit. Would have been helpful to have some damage return to kill the bouncing spiked balls, but I didn't, and they hit me a lot too. Anyway, I limped out of that battle with a little over 100 health remaining, not satisfied at all with the performance. The basement was the only region left to explore, and I made it through a decent portion of that, but I was killed by one of the swinging chain ball monsters when I played a small, enclosed room poorly. Again, I was never really happy with this character even though I cleared two bosses and brought back 83k gold. Maybe I'm too hard on myself.
Unlock: Imperial Sword, Attack Up x10, Health Up x4, Armor Up x4, Equip Up
13) Level 160 (Health 30, Attack 49, Armor 20, Equip 33, Mana 4, Gold Gain 5, Potion 5, Crit Chance 2, Crit Damage 1, Miscellaneous 11): 99,303g
Tunnel Vision. Now I had a bright yellow sword instead of a blue one, still quite colorful. I went through the tower first, where I found the Guardian Cape; may or may not decide to wear that after this run is over. The tower was noteworthy for having two different "kill all enemies" fairy chest rooms, both of them ridiculously hard and packed full of monsters. I cleared one of them, left the other one for potential pickup later. Treasure chests gave me more Cape choices following this run, as the Sky Cape, Retribution Cape, and Royal Cape also appeared. I'd have to figure something out afterwards. I also grabbed the Slayer Bracers in a chest hidden in the basement, which would be a nice upgrade in that slot. Bonus crit chance and damage is always nice on physical fighters. After running through the tower and castle, I headed down to the basement, and upon finding the boss door with full health, went inside. There wasn't too much to say about the Heredotus battle; I fought the blobs very carefully, focused on taking out the small ones first, and minimized the total number of opponents on the screen. I won with about half health remaining, and honestly could have done better.
After beating Herodotus, I went through the full dungeon and cleared it out. That included beating that fairy chest room I had left earlier in the tower, and going back to kill a Sallos (painting) miniboss after everything else was done. Sallos gave me the Dragon Sword after a tough fight, which really made it feel worthwhile. With everything cleared out, I ventured inside the final boss door to take on Johannes and The Fountain, only to die in humiliating fashion. Can't win 'em all, it seems. Despite finding all those capes, I decided to stick with the Ranger Cape's crit chance and crit damage over the choices of extra armor (Guardian Cape), two extra air jumps (Sky Cape), return damage (Retribution Cape), and flight (Sky Cape). The Dragon Sword and Slayer Limbs though, they were both upgrades in their slots. And the rest of the money (80k) went into a whole truck load of upgrades.
Unlock: Dragon Sword, Slayer Limbs, Health Up x10, Attack Up x8, Equip Up x2, Armor Up
14) Level 181 (Health 40, Attack 57, Armor 21, Equip 35, Mana 4, Gold Gain 5, Potion 5, Crit Chance 2, Crit Damage 1, Miscellaneous 11): 117,552g
Savant, Coprolalia. With that latest round of upgrades, I now had 930 health to play around with. Starting to get pretty silly, and I still had room for 35 more points in health to go. I really tore through the dungeon on this particular run, with the additional health and damage seeming to make a difference. Many of the monsters in the castle would die with a single hit, especially if I landed a critical strike (12% chance). I went through the dungeon in my normal lategame order: tower -> basement -> forest, with the castle serving as the linking point between the other areas. I found the Hermes Shoes in a secret shrine, and took advantage of that to run on some spiked floors in a number of areas. Always enjoy that, you can see my Barbarian standing nonchalantly on the spikes in the picture above. Anyway, I found a few more pieces of Slayer gear that I might decide to wear afterwards, and a bunch of outdated stuff that will never see the light of day. (Lots of Retribution equipment and the Holy Sword, all sadly outdated.) I fought Botis and Sallos again, otherwise not much to report. I had little worry that I would be killed, and I simply wanted another full dungeon clear and ~100k gold in my pocket before facing the final bosses.
These two were pretty anticlimatic on this repeat attempt. Johannes wasn't too terribly bad this time around, could have gone better, but I was full health when I reached the second half of the battle. The Fountain was kind of a sloppy battle on my part, as I took a whole bunch of unnecessary hits that could have been dodged. Still, I had the Barbarian shout in my back pocket, and I did get good use out of it. The Fountain dropped when I still had about half my HP bar remaining, so it wasn't too close. New Game Plus cleared with only three Barbarians used (!) Two successful runs down, one more round to go.
Here's where the victress of NG+ difficulty, Lady Antoinette III, stood at the entrance to the gates of Hell (err, NG++ mode!)
I had upgraded my equipment to Royal and Slayer gear for the most part, aside from the Dragon Sword. I was hoping to find the Royal Sword for that slot soonish. Stat points had heavily gone into pumping damage, which I knew I would require to cut through the massive enemy life totals of NG++ difficulty. There were still plenty of points available to put into health, but with 930 HP from innate Barbarian tankiness, I felt that I was in pretty good shape there for the moment. I needed 10 more runes to finish the set at this point, 45/55 complete. 45 runes from 15 total trips through the dungeon thus far (counting the two trips made by Barbarian #11) felt pretty good to me. I took a page out of my Paladin's NG++ playbook here, and sank most of the gold from the NG+ victory into maxing out critical strike chance (25/25 upgrades). This raised my overall crit chance from 12% to 62%, and hopefully would give me a chance against the huge healthbars of the monsters on this difficulty level. I needed about 100k more gold to max out Attack damage. I intended to grab that, and then max health and armor as best I could. We'd see what happened.
Unlock: Slayer Sword, Crit Chance Up x23 (maxed), Attack Up x3, Health Up, Crit Damage Up
14) Level 209 (Health 41, Attack 60, Armor 21, Equip 35, Mana 4, Gold Gain 5, Potion 5, Crit Chance 25, Crit Damage 2, Miscellaneous 11): 108,456g
Now it gets hard. 
My biggest worry was not having enough damage to clear the enemies in reasonable fashion, which is why I sank so much gold into damage and crit upgrades. I was now doing 142 normal damage and 291 damage from crits, which meant that it took quite a few hits to down opponents. Something like 6-7 with no crits, and half that when crits landed. Doable, if not easy. NG++ was just as brutal as I remembered it to be, with top tier monsters everywhere and punishing damage any time I took a hit. I played carefully, and managed to get through the whole castle and the whole forest, before dying in the second or third room of the tower. That meant over 100k gold, something that I was quite happy with. The biggest find was the Slayer Cape in a chest in the forest, which is a straight upgrade over the Ranger Cape I'd been wearing forever. I was now outfitted in all Royal and Slayer gear, a bit of a drab group to be honest. I continued to pump damage with the rest of my gold, since that was what would benefit me the most. I need to drop the enemies in fewer swings - I already had plenty of health.
Unlock: Slayer Cape, Attack Up x10, Health Up x4, Equip Up x2
15) Level 225 (Health 45, Attack 70, Armor 21, Equip 37, Mana 4, Gold Gain 5, Potion 5, Crit Chance 25, Crit Damage 2, Miscellaneous 11): 73,789g
Stereo Blind, EDS. I just cleared quadruple digits on the health bar, clocking in at 1005 HP. As much as that sounds, many of these enemies could do over 100 damage per hit, and their attacks filled the screen with projectiles. I still had to play very carefully. (I also should point out that my 15th Archmage was Level 35, compared to Level 225 for this Barbarian. This class is a wee bit stronger!) This actual run was fairly uninteresting. I didn't do as well as my previous run, only making it through the castle and part of the forest. It was a mixture of some crazy room layouts, fewer chickens dropping along my path, and simple bad play from me. Rooms like the one above were, umm, "interesting" to try and clear out. Still, I did bring back 73k gold, so I guess I couldn't complain too much. I used the money to finish maxing out the Attack stat (75/75), put six more points into health, and dropped the last two into more crit damage. Finished up with 34 gold remaining, almost perfect.
Unlock: Attack Up x5 (maxed), Health Up x6, Crit Damage Up x2
16) Level 238 (Health 51, Attack 75, Armor 21, Equip 37, Mana 4, Gold Gain 5, Potion 5, Crit Chance 25, Crit Damage 4, Miscellaneous 11): 116,251g
No traits on this guy, just the fairly useless blade wall spell. (I later found the axe spell in the castle and swapped to that.) This run got off to a horrible start, with a frankly insane third room, and I was yelling at myself for taking so much damage early on. It looked like it was going to be a useless character. Then I was able to step up my play, and began to tackle the dungeon in earnest. For whatever reason, I was able to start clearing long stretches without taking damage, some very fine work if I do say so. I found the castle boss door with full life, went inside and bested Khidr while taking only a single hit. Still had over 1000 life remaining, ha! He gave me a strength bonus... and two magic damage bonuses. Sigh. Fought Botis in the forest, taking one hit (for 140 damage!) in the process, which resulted in the Dragon Cape dropping. I sure wish that I had seen that earlier, but at this point I preferred the Slayer Cape for the crit chance and damage. I cleared out the first two areas, died in the very last room of the forest, which was totally insane and one of the most unfair rooms I've ever seen. (It is pictured above; the skeleton bone throwers and the wolves made this an absolute deathtrap.) I should have walked away from it, but I can never back away from a challenge. 
I poured the sizable gold returns into health, armor, and a whole bunch of crit damage increases. I now had 62% crit chance, and 280% crit damage. Since base strength was only 165, I was relying on those crits to deal damage.
Unlock: Crit Damage Up x13, Health Up x9, Armor Up x4
17) Level 264 (Health 60, Attack 75, Armor 25, Equip 37, Mana 4, Gold Gain 5, Potion 5, Crit Chance 25, Crit Damage 17, Miscellaneous 11): 278,624g
Ambivelous, OCD traits. This run got off to a good start, as I made it through most of the castle without issue. For whatever reason, I headed into the forest and cleared that out before anything else, which is highly unusual for me. I just ended up in there and kept going until it was all done. I ventured into the boss door when I had near full health, and easily defeated Alexander. He hit my Barbarian one time and did all of 80 damage, which was pretty laughable given my 1200 health. Next I went into the tower, and managed to make it through there fairly well all things considered. I fought Ponce de Leon when I found the boss door, and that fight didn't go as well for me. I took a bunch of hits and lost about half my overall health. It was a sloppy fight, could have been a lot better. Oh well. Then it was down into the basement, which was pretty rough. I didn't have enough health remaining to try fighting Herodotus, so I tried to clear out as much of the basement as posssible. I managed to get nearly all of it done, before falling in one of the last remaining rooms:
Sadly, I had forgotten about a fountain refill in the second room of the castle, which would have restored 550 health and almost certainly allowed me to get a full dungeon clear. Nevertheless, I amassed my largest gold total ever with 278k on this run while defeating two bosses in the process. I also won the dagger throwing minigame (in return for a Strength bonus) and found the last few missing runes; the last fairy chest that I found had a health stat bonus inside. From here on out, they would all produce stat gains. I was fortunate enough to capture this run for YouTube, so it can be watched in real time with commentary. I used the huge pile of cash to max out the health stat (75/75), max out critical damage (25/25), and put the rest into 22 armor upgrades, which left that category at 47/50 points. All told, that was 45 upgrades purchased at once! 
Yeah, I was pretty much reaching the end of the NG++ run here.
Unlock: Health Up x15 (maxed), Crit Damage Up x8 (maxed), Armor Up x22
18) Level 309 (Health 75, Attack 75, Armor 47, Equip 37, Mana 4, Gold Gain 5, Potion 5, Crit Chance 25, Crit Damage 25, Miscellaneous 11): 294,360g
Stereo Blind, OCD traits. With the health stat maxed, I now had 1478 overall HP to play around with. The health bar stretched across almost a third of the screen. I also had 167 base damage, 62% crit chance, and 320% crit damage, meaning critical strikes did 534 damage against the 167 damage of a normal attack. If I could only find the Royal or Dark Swords, then I'd be doing substantially more damage, due to their higher base rate compared to my current Slayer Sword. I went through the tower first, and it was remarkable for its stinginess in terms of drops. I cleared out 20 rooms in there without even one chicken dropping, and only one flask for MP refill. That was horribly unlucky, and I dropped all the way down to 200 HP in the process. Had to go back to the uncleared parts of the castle to restore health again. A fountain that turned up in the castle was my savior, giving back hundreds of hit points and restoring sanity to the run. The forest was generous to me with a lot of chicken drops, but I still could never quite manage to refill that huge health bar completely. Still, I made it through without having to dip into my saved chickens and flasks outside the boss rooms. Finally, I went down into the basement, which was as rough as ever. I was forced to go back and eat two chickens at times when my health dropped dangerously low, but I did get it all cleared out in the end. (Everything except one Sallos which I didn't want to fight.) I also did pick up a good half dozen fairy chests on this run for stat boosts, unfortunately which tilted yet again towards mana crystals for some reason. What was it with my Barbarian and getting mana upgrades as stat bonuses, heh.
Now I raided all my saved resources to enter the Herodotus battle with full health and mana. This fight wasn't especially difficult, and if anything seemed to be easier than in NG+ difficulty. I smashed the blobs and concentrated on killing the smallest ones, and didn't have any real trouble. I only lost about 150 health over the course of the whole encounter, largely due to my Vampirism refilling hit points with each blob and flying mage kill in the chamber. So from there I went on and entered the final boss chamber, where both of them were complete weaklings. Johannes jumped around a lot, but only managed to hit me one time. I simply shouted away his axes and knocked him back when he got close. And the Fountain was even weaker, as he didnt manage to land a single blow, and went down under a hail of melee attacks. They were unquestionably easier here than in NG+ mode, no doubt due to all of the critical strike damage that I had accumulated. Their health bars probably should have been larger. In any case, that meant another new personal gold record for me at 294k (I was kind of disappointed, I wanted 300k) and a full dungeon clear plus final boss clear of NG++ difficulty. It had only taken 18 total Barbarians. Yeesh, this class is strong! 
These were my final stats on finishing NG++ difficulty. I had just under 1500 HP with the maxed health stat, and pretty good damage to pair with it. Equipment was still made up of a mixture of Slayer and Royal gear; I never found the Royal Sword that I wanted, nor any of the Black items. They don't seem to drop commonly until reaching NG+++ (NG+3) difficulty level, which is why my characters in this venture rarely seem to turn them up. I was frankly amazed that I managed to max out nearly everything in just 18 total Barbarian characters. At the same point in my Archmage quest, poor Archmage #18 was only Level 44 and brough back 3700 gold. Barbarian #18 beat NG++ mode at Level 309 and brought back 294,000 gold. Yikes, that comparison certainly tilted a bit in favor of the big old Barbarian...
And so that marked the end of the Barbarian's quest, almost certainly the most overpowered class in Rogue Legacy. Or... at least it would be the finish line for any other class. I decided that I would play on, just a little bit further, to see how things fared in NG+++ (NG+3) difficulty. After all, this was the Barbarian. If any class could keep going, this was the one.
This was my best run on NG+3 mode, as I broke my previous gold record and put up 371k as my new best score. Even though this beat my previous record by almost 100k, I made a lot of mistakes on this run and didn't even finish the basement before dying. I knew that I could do better than this. So I kept playing a bit further, and managed to improve on that score:
This Barbarian cleared all four sections of the dungeon and also defeated the final two bosses, accumulating a massive 483k gold in the process. (With Colorblind trait to boot, and yes, Colorblind along with the darkness in the basement area is really annoying to deal with!) So now that I cleared NG+3 out to completion, it was finally time for my Barbarians to ride off into the sunset... Err, wait a minute... seems to be one more customer here:
NG+3 apparently wasn't hard enough. Not for the Barbarian. 
I went ahead and tried NG+4 difficulty, and found that I could make progress there as well, by making very heavy use of the Barbarian shout, which I could now spam essentially at will with the mana stat maxed out along with Mana Cost Down completed. 15 MP per shout with 500+ mana made for a sore voice from endless shouting. And I had to play almost perfectly, due to the insane amount of damage and health that these monsters possessed. Still, the Barbarian was strong enough to keep right on going, if not easily, and on my best run I cleared out the entire dungeon yet again, followed by clearing Khidr, Alexander, and Ponce de Leon. The picture above is taken at the end of the Ponce fight, when I sadly had no more resources left to raid for additional health. I died against Herodotus, but not before this run picked up an absolutely stunning 700,000 gold in one go. (I started with 70k gold in pocket, which I could not spend away because I already had all upgrades and equipment and runes. After subtracting that out, this run was right at the 700k total.) Then I turned on the Architect with the following Barbarian, defeated Herodotus and the final two bosses, and entered NG+5 difficulty.
That would be it, however. NG+5 was finally the breaking point; the average monster had 1500 health at this point, requiring 8-10 swings of the sword to kill, and an average hit would deal over 200 damage to my Barbarians. One time a Gradiator hit me and did 350 damage. Despite topping the 1600 HP mark, I could not sustain through that level of monster health and damage. (I mean, I could farm fairy chests endlessly for stat bonuses, but where would the fun or sport be in that?) NG+5 was the final barrier; I could pull back some 300k runs at times, but I never got anywhere close to the 700k total from NG+4. My Barbarians had finally reached their limit.
But what a limit it was! It was the sort of limit that other classes could only dream of aspiring towards. Even though I still needed to play through several more classes, I felt pretty confident in stating that the Barbarian is the strongest class in the game. You really can't beat the combination of massive health along with the amazing Barbarian shout. Next time I would have to try something harder, just to keep myself from getting soft. By popular request, the Lich would be the next up to bat. 
