Next up was the Sealed Cave in the game's storyline. Except - the whole dungeon is crawling with Trap Doors, which dish out instant kills that can't be dodged or avoided. Ugh, how to get past them with only one character? The online solo guides suggested leveling up Cecil to some ungodly high point, like 75 or 80! I believed I had a better way, however...
First things first, as I picked up the Diamond set of armor in the dwarf village of Tomra. Now I could finally get rid of my Flame and Blizzard armors - I was almost out of inventory space. My target was the Sylph Cave, which contained a new weapon that I hoped would allow me to get past the dreaded Trap Doors in the Sealed Cave. Cecil made his way through the underground area, running from the dangerous fights and picking up some experience from the easier ones. When I made my way down to the bottom level, I ran into a bit of a problem. The chest I wanted was guarded by more monsters, four Molbols which possessed a nasty breath attack. This inflicted every conceivable status ailment at once (toad, poison, mute, confuse, mini, etc.) and made normal fighting impossible. A single round of attacks once Cecil had been breathed upon inflicted thousands of damage and inevitably killed him. So I tried breaking out my most powerful items as spells that I had saved up:
The rare Red Fang attack does the same damage as the Jinn ("Ifrit") summon's Hellfire. I could do about 2000 damage to each target this way. Unfortunately, the Molbols each had 4200 hit points, and I didn't have a second Red Fang to play around with. None of the other elements were nearly as effective as fire; I tried ice and lightning items to little effect. I had to come up with some other way to win this battle!
If directly attacking with spell damage didn't work, then the best course of action was to try something indirect. I had Cecil use the Silver Hourglass item, which casts "Stop" on all targets. These monsters didn't have the boss flag tagged, so they were easy prey. While the Molbols were frozen in time, they couldn't use their breath attack! I had Cecil use his Red Fang again (remember, this is a different play-through after getting wiped out before) to take all of the Molbols to half life, then started attacking. Two hits was enough to finish off each opponent. I had to use a second Silver Hourglass halfway through the fight, but it worked! None of the enemies ever got a chance to attack. Cecil walked away with the desired goal:
The Avenger Sword! This unique weapon has several key properties. First, it's two-handed and doesn't allow a shield to be used in the other hand, reducing defense significantly. Secondly, the Avenger does good damage (more than Cecil's current weapons) and increases Strength by 10, for at least one additional attack multiplier. Finally and most importantly, while equipped with the Avenger the user is Berserked at all times! Usually that's a bad thing, as a berserked character can't tell friend from foe and attacks randomly. But what if there are no allies to injure? Aha! See what I mean? 
The Berserk spell itself is truly powerful, increasing base damage by 50%. Fifty percent! Suddenly Cecil was banging out 2500+ damage on every attack. I couldn't control who he attacked, or cast White magic, or even use items - none of which would matter against the Trap Doors. Now I had my answer, or at least I hoped so.
The way the Trap Doors work is that they cast "Target" on their first round of action, which indicates who they are going to attack. Then on their second round, they initiate "Dimention 9", a one-hit insta-kill that can't be dodged or avoided. To get past them, Cecil would have to attack twice and inflict 5000 damage before the Trap Door could get off its Demolish attack. I made my first stab at this when Cecil was level 55. Short answer: it didn't work. Cecil could only act once before the Trap Door went twice, making action impossible. He needed more Agility (more than 43), and the only cure for that was some more levels. Still, I didn't need to bore myself yet; there was more of the Sylvan Cave still to explore, and I gained another level just doing that. Then there was the Phantom Beast Cave, leading down to Asura and Leviathan. I had to go down there anyway to get the Rat Tail and Defender Sword (another nice weapon), might as well do it now, right?
OK, took care of all that, Cecil gaining another two levels in the process. Now at level 58, with 45 Agility. Enough to fight the Trap Doors? Nope. How about level 60, where Cecil picked up another stat increase?
Sorry, no dice. Looks like the only answer... is to grind out some levels. Dang it. 
I had hoped to avoid this by going to such lengths to get my hand on the Avenger Sword. Berserk status not only boosts attack damage, but actually speeds up the target slightly as well, attacking a little bit more frequently. Just equipping the Avenger Sword gave Cecil +10 to Agility too! And that was the problem here, not enough speed. Cecil was already doing about 2500 damage, enough to take out those Trap Doors in two hits. The problem was that he was dying before he could get both of those attacks off.
So off I go to fight a lot of random encounters. Level 62, and 47 Agility - no luck. Level 64, 48 Agility, still no. Every two levels Cecil would get an additional point, and I would try again, only to be sent back frustrated. You know, this part of the game design is not particularly well done, IMO. I'm not a big fan of the impossible-to-avoid death attacks. In the original Final Fantasy, there's always a chance that you'll dodge the death spells, or get lucky with critical hits and misses from the bosses. There's a lot less randomness in this game, which means that situations like this turn into real variant busters. And I know, I know - you're not supposed to be doing the game with one character! Still, I feel like this could have, should have been handled better.
Up to level 70, all of the stat increases are fixed with each level up. After that, they are random, and the stats can even go down! Not sure what crack Square was smoking when they came up with that. Cecil's best possible level up grants him two points in each stat, so I saved the game right before leveling up and waited until I got two points in Agility with each one. Finally, at level 73, Cecil hit 56 Agility and I made my usual attempt, not expecting anything special:
Holy crap! That actually worked. I didn't even take a picture the first time, I was so surprised. (Fortunately, there's a lot of Trap Doors in this dungeon.) Well, looks like we have our answer: you need exactly 56 Agility to get off two attacks before the Trap Doors crush the living daylights out of a solo character. Oddly enough, Cecil would still get killed if I ran the battle at the default speed ("3"). I could only win by setting the battle speed to its lowest possible setting ("6"). Wonder why that was? It certainly made a difference!
The one downside is that Cecil had picked up 15 additional levels in the interum while grinding up to defeat those darn Trap Doors. He was now doing an obscene (16x) 122 Attack, and with the Berserk bonus that was actually (16x) 183! Now everthing that was NOT a Trap Door was little more than dead meat. It reminded me of Sirian's long-standing comment about Diablo 2: too much Gap. In order to be strong enough to beat the really nasty foes, my variant became all-powerful against everything else. That's a bit of a shame, because the earlier portions of this game were really, really entertaining.
I took out every last Trap Door in the Sealed Cave while running the dungeon. Those bastards had it coming. 
Anyway, crushing all those doors had Cecil reach level 75 by the end of the cave. I now prepared for a similar battle against the Demon Wall:
This boss slowly advances towards the party, and when it reaches you, dishes out more unblockable death attacks. It's actually a pretty cool concept, much better than the Trap Door (which, in a normal playthrough, will ALWAYS kill at least one party member in each fight). For the Solo Cecil variant, I had to inflict 28,000 damage and kill the boss before the wall reached the right side of the screen and finished off my character. Creeping doom indeed!
I decided to take a stab at the Demon Wall with my standard setup from the Trap Doors: move Cecil to the front row, slow down the battle speed again to minimum, and let the game run on auto-combat with the Avenger Sword's berserk status. Each attack from Cecil was doing roughly 3000-4200 damage, so I would need to get in about eight attacks to kill the boss. As it turns out, I managed to get seven of them before being crushed, and inflicted just over 25k damage overall. (I keep a calculator with me for boss battles to keep track!) Clearly, that wasn't going to work. Before giving up and heading off to level up my Agility again, I resolved to try out some of the items saved in inventory. The Copper and Silver Hourglasses didn't work - evidently the Demon Wall is immune to the Stop spell. OK, what about the "SpiderWeb" item, which casts Slow? To my surprise, this worked!
New strategy: go into the battle with the Defender Sword equipped (so that Cecil can use items - I didn't even get to select commands when he was using the Avenger Sword!) On the first round, use a SpiderWeb to slow down the boss. Second round, swap back to the Avenger Sword for mucho damage, and then hack away. As it turned out, this bought me just enough time to get in eight attacks. Cecil rolled on the "high" side of his damage potential, mostly around 4000 with each attack, and I downed the Demon Wall right before it could crush him out of existence!
Got it on the second real try, after some experimentation. No need to level up - what a glorious fight! This is my absolute favorite part about these games, devising a strategy for each unique boss battle and then seeing the execution through to completion. The Solo Cecil guide at GameFAQs states that the only way to win this fight is to level up to 85, and rely on higher Agility. Well I did it ten levels lower, because I actually had a plan besides "go level up." Ha! 
I stocked up on a few key items before getting ready to head to the moon. Most importantly, I picked up Excalibur for Cecil from the blacksmith. The damage output was insane: (15x) 202 Attack! That's more than the Avenger Sword, even with the berserk 50% bonus, plus I could control Cecil and equip a shield. Upgrade in every possible way.
The first thing I did on the moon was go and purchase seven more Elixirs from the Namingway cave. That was the only useful thing left to do with my money at this point. Next, I went and picked up FuSoYa in the central palace to advance the plot. Killed off his fat behind immediately, of course. I then ran the Bahamut Cave, to pick up the Genji equipment inside for Cecil. Every little bit of additional armor helps. The Behemoths in there were extremely easy; they won't use their "Storm" ability unless you cast magic at them. They responded to Cecil's attacks with physical attacks of their own, which were pointless. And for a solo character, they gave insanely good experience: 58,000 each! Without making any attempt to grind, Cecil gained four levels on the moon and was level 79 by the time I was ready to return to earth.
I wanted to fight Bahamut, but hadn't beaten Leviathan yet. Oops. (Could have beaten him, but Asura was much tougher for a character that couldn't cast Wall, with her endless self-healing.) Have to remember to go back and try that again now that Cecil had Excalibur.
The enemies in the Giant of Babil were easy, and gave monstrous experience for a solo character. Cecil gained a couple of levels without me even trying. As usual, this dungeon also had a double boss to contend with. The first was the reunification of the four Fiends into one lengthy battle, starting with Milon. He was the easiest of the four, allowing me to kill off my companions (who had been revived again by Rubicant). Milon would cast Curse on Cecil, then follow with four rounds of weak attacks. Rinse and repeat. I countered the curse with the "cross" item, which cures the status ailment, then mixed in attacking and healing with Cure 2 as necessary. Pretty basic stuff. Next up, Rubicant:
What a nasty, nasty boss. He had a similarly basic AI pattern: cast Fire 2, Fire 3, and Flame Tornado in order, then repeat. Although Fire 2 did negligible damage, Fire 3 would do around 1000 per casting, and the nasty Flame Tornado about anywhere from 1000-2000 damage! The only possible way to recover from this kind of damage was to keep using Elixirs when Cecil's health dropped low. I should also mention that each of the four Fiends had 28,000 hit points, and as you can see, Cecil was doing around 2000 with each attack. This made for a long and nerve-wracking encounter. There was one point where Rubicant could have killed Cecil with his Flame Tornado; I had 1500 hit points left, and his attack did about 1200 damage. Whew. Used an Elixir and survived to fight on.
Eventually Rubicant was replaced by Kainozzo. He would attack three times and then cast the deadly Big Wave:
It did exactly 1780 damage each time; probably a percentage of his maximum hit points or something like that. Kainozzo was significantly easier than Rubicant because he actually gave me some "down time" between uses of Big Wave - the physical attacks were completely useless against Cecil's armor. However, I was still forced to burn through more Elixirs, since Cure 2 simply could not heal the damage fast enough. Cecil could get in about five attacks between uses, but the well was really starting to run dry by the end of the fight.
Last was the second incarnation of Valvalis. Remember how tough she was the first time around? Valvalis continued using the same tricks, alternating between an extremely weak physical attack, a "Maelstrom" tornado attack that dropped Cecil's hit points down below 10, and a "Fingertip" stoning attack. However, I was prepared this second time around, and equipped Cecil with the Aegis Shield, which prevents petrification. One of her attack forms was completely neutralized! No longer needing to cure both hit points and status effects, this was an easy fight. For whatever reason, Valvalis also took vastly more damage from Cecil's Excalibur than the other Fiends, something like 6000-7000 per attack! Not sure why she was weak to Holy elemental; maybe a coding bug? You'd think that Milon and his undead-ness would be the weak one...
All told, I needed eight Elixirs for this fight - eight! That's more than I had found in chests throughout the entire game so far. Thank goodness for that Namingway vendor on the moon that sells them. If you don't know about that place, the Solo Cecil challenge is probably just about impossible. Interestingly, the Solo Cecil guide at GameFAQs doesn't suggest that this fight is terribly difficult, and states he only had to use three Elixirs. I don't recall this fight being difficult when I played the game as kid (on the American version) either. I can only guess that the Japanese version is significantly harder here. Interesting.
The Attacker, Defender, and CPU orbs that make up the second boss were pathetic. They had exactly one attack: a "Laser" from the Attacker that did 10% of Cecil's max hit point total (712 damage) each round of combat. Yawn. I killed the Defender, CPU, and Attacker in order with zero danger whatsoever. They were not worthy of a screenshot.
On to the moon! But wait, first we have some unfinished business on earth...
Cecil's back! 
With Excalibur in tow, now I had the chance to do enough damage to cut through Asura's endless self-healing. Her castings of Cure 3 healed back roughly 2000-3000 damage each, and as you can see, Cecil was doing slightly more damage than that with each attack. I moved him up to the front row to increase the output too. Now that Cecil was encased in beastly armor, he was essentially invulnerable to Asura's attacks. After a lengthy fight, she went down.
That opened the door to a fight with Leviathan. He had a simple attack pattern as well: a casting of "Big Wave", which did exactly 1815 damage with each use, followed by two castings of Ice 2, which usually incurred about 300-500 damage. In other words, very similar to the Kainozzo fight I had just done, only slightly more dangerous, since Leviathan's Big Wave was accompanied by ice attacks instead of physical ones. There wasn't much strategy possible here beyond attack and heal as necessary with Elixirs. It required two drinks to down the boss successfully. I did screw up slightly by keeping Cecil in the back row, which was pointless because all of the attacks from Leviathan were magical. D'oh!
Odin was easy. Cecil was so over-leveled that I could just attack endlessly and win the battle. Odin's one charging attack did do almost 4000 damage to Cecil, which was quite a sight to see.
Back to the moon, and on to Bahamut. His big attack is to count down from 5 to 0 and then unleash a devastating "Mega Flare" attack that does immense damage. We're talking 5000+, which could even threaten my massively high level Cecil. The standard strategy is to cast Wall on your party members and reflect the attack back on him. If only I had access to the Wall spell!
Oh wait - I do! There's an item called the "Lunar Curtain" that casts Wall on the user in battle. Perfect timing here, eh? I had to use two of them, and the battle ended up being cake.
Why am I doing these unnecessary boss fights? I dunno. Because I can, I guess - and it's fun. On some level, it was good to know that Rydia could use all these awesome summons if needed. Call it guilt for killing her off so many times. On another note, I did finally find an FAQ with some of the damage calculations in it, written by Ben Siron. (You can look at it here, if desired.) Unfortunately it's rather poorly written, with way too much jargonistic terminology and unclear algebraic formulas. Note to future guide writers: try to give some examples with real numbers! According to the guide, the basic damage calculation is to generate a random number between Attack and Attack * 1.5, then multiply this by the attack multiplier and subtract out defense times defense multiplier. This works really well for the mid- to late-game, when a dozen hits are being averaged together, but I still believe that each hit is calculated separately and added together, rather than there being one unified attack that gets multiplied. At least the guide cleared up a lot of other stuff, like how magical damage is calculated.
Time to enter the final dungeon in the lunar underground - after loading up on more Elixirs, of course. It took a couple of trips to clear out the treasures on the first three dungeon floors, with the multiple branching paths down there. I came across the Murasame while exploring, and decided to take on the boss guarding it: the White Dragon. This boss had a Valvalis-like attack pattern, attacking several times and then casting "Maelstrom" (Weak) and dropping Cecil's hit points down to nil. No stoning, fortunately. I used the same pattern in response, attacking frequently and cast Cure 1 (no need to use more) in response to Maelstrom. Since its own attacks never did more than 1 damage, this was a rather easy fight:
Caught him fading away into the purple haze. The next couple floors below B3 began turning up the Crystal equipment, the best stuff in the game for Cecil. Each chest tended to be guarded by high-end monsters, like Red/Blue Dragons and Behemoths. All three of these monster types were easy, their physical attacks completely ineffective and their rare magical ones not strong enough to worry. After loading up on this gear, I went to complete the set by going for the Crystal Sword, Cecil's ultimate weapon:
Of course I had to get past Dark Bahamut, the weapon's guardian first! He opened with Mega Flare, then went into another predictable pattern: Wall on himself, then a bunch of Flares reflected off himself onto Cecil, and ending with a casting of Heal on himself (6000 hp recovered). Then repeat. Each Flare usually did about 500-1000 damage, and many of them missed entirely (?) for reasons I don't understand. Whatever, cool! I attacked non-stop with Cecil, and healed when his hit points got low. One Elixir was enough to win this fight. Now I had the best weapon in the entire game. The Crystal Sword ("Ragnarok" in this version) took Cecil up to (16x) 246 Attack - insane!
That took care of most of the optional bosses. I did fight Ogopogo, the guardian of the Masamune (essentially a stronger version of Leviathan) and managed to kill him, but I had to use several Elixirs and so I didn't save the fight. Cecil had nine of them in inventory at this point, and I didn't know how many would be needed for the final boss. I had no desire to warp out to buy more and have to walk all the way back down to the bottom of the last dungone either! The other two optional bosses were not good fights for Cecil. Plague always casts Doom to start the battle, and there was no way I could kill him before that ticked down to zero and killed Cecil. The two Lunar Dragons cast Virus ("Bio") in endless sucession, and it was really strong! 1800 damage per casting, per dragon! MAYBE I could have done that fight, by going Attack/Elixir, Attack/Elixir, but it just wasn't worth it. Not with limited quantitied of Elixirs on hand, and for a treasure Cecil couldn't even use.
And so we come to the end:
Cecil reached level 91, and maxed Strength and Vitality with ease. What was surprising was how high his Will stat ended up: 78 is really good! That's about where Rosa would be in a normal game that finished around level 50-60. Cecil's Cure 2s were healing back over 1000 hit points by end of game, no joke. He was limited only by his extremely small selection of white magic spells. Notice also that his Agility is actually LOWER now than it was twenty levels earlier when Cecil was fighting those nasty Trap Doors. That's because the Avenger Sword gave +10 to Agility - right when I needed it most! What a useful weapon that had been.
I reached the bottom floor without issue, and the ending cinematic sequence began:
The only reason I'm showing this picture is to comment on how the Zeromus Form One design is my favorite 2D monster sprite of all time. Look at that thing! It's hard to describe, all sleek lines and ghastly teeth/claws. It doesn't hurt either that this form wrecks the living daylights out of Golbez and FuSoYa. (Note the little bug here in the translation: Golbez is accidentally listed as "Gilbert", which is the Japanese name for Edward. Whoops!) The Zeromus Form Two is a generic weird-looking alien... thing. Looks like something out of a shoot-em-up game, like Gradius or R-Type. Not something that fits with Final Fantasy. They could have done better.
And here it is, pictured above. Zeromus had only three attack patterns that I noticed: casting Big Bang (1500ish damage), casting Flare (about 2000 damage!) and casting Black Hole, which removes any positive status effects like Haste or Berserk. I couldn't speed up Cecil or buff his attack power in any way, so I concentrated on attacking. Whenever hit points dropped below 3000, I used an Elixir. Didn't want to take any chances - I did not want to have to walk down four floors and sit through the cinematic scenes a second time. It was an oddly quiet battle, to be honest. Usually there's all sorts of craziness going on, with Kain Jumping, Edge Darting, and the girls firing off magic. This was so different: just Cecil attacking, and Zeromus countering with Big Bang. Long seconds passed with neither side acting at all, very strange.
Anyway, after some of the earlier battles fought in this variant, Zeromus was a cinch. I made sure that Cecil was never in real danger, and he died after about 20-25 attacks. Used four Elixirs, with plenty more remaining in inventory:
And the obligatory screenshot of the boss crumbling to signify victory. Yay! 
Some concluding thoughts. I'm glad first of all that I decided to go with the translated Japanese version, rather than the American Final Fantasy 2. The challenge level was higher, the monsters hit harder and acted faster, and some bosses had abilities not present in the American version. At the same time, however, I had access to all sorts of "items as spells" that weren't present in our version, which enormously enriched the gameplay. Inventing uses for those Hourglasses, Bomb Fragments, Haste Shoes, and Lunar Curtains was where I derived the most fun!
Top three hardest fights, let's see... I would put the Valvalis one as the worst. Remember how I had to grind out five levels, plus spend four or five hours in various failed attempts, plus still get lucky to win that one? Lord, what a pain. I never, EVER want to try that one again. Kainozzo was probably the second worst. Even though I won on the first try, it took serious luck with getting a Berzerked critical hit at the right moment to overtake his endless self-healing. I've heard he heals something like 200-300 hp in the American version (rather than 500 hp in the Japanese one), so that was one fight where I really felt the extra difficulty. Third would be the Lugae battle, which was very tough but DID have a viable solution, once I was able to find it. Unlike the other two, you could win that fight with skill and careful use of items, rather than simple luck. I don't count the Trap Door encounters as real "fights" at all, by the way. Just obstacles to be overcome. Do you have enough Agility to attack twice? If yes, congrats, you win automatically. If not, sorry, nothing you do can possibly win the battle. That's pretty sad game design there, at least from the perspective of a solo character. That was easily the least-fun part of this variant.
In conclusion, as entertaining as this was, Final Fantasy 4 is not a good game for running variants. Too little control over your own party, with characters coming and going, and too little control over their abilities. You can't mix and max classes, or pick an oddball party, or anything along those lines. Solo Cecil works mostly because he's the only character who remains in your group the entire game. And I've wanted to do this variant for over ten years now, so I finally went ahead and did it! But there's not much point in trying to push this game further. T-Hawk was right: Final Fantasy 5 is the game for variantism. I'd like to play a game or two there to learn the system, doing things the "right" way, before branching off into wackiness. So don't be surprised to see something popping up on the forgotten SNES Final Fantasy sometime down the road.
As always, thanks for reading. See you later.
