Final Fantasy 7: Ultimate Nerf War Crisis HardCore or something
Hardest boss in the game defeated?
So. FF7CC on Hard. It starts off insanely difficult (learning the system + not very many save points in the first fight-Wutai mission), but then becomes basically doable and fun by the middle. This is thanks to the ruthless defensive setup Zack can use - for the middle of the game, I pretty much always had 2 HP+ materias, Barrier, MBarrier, a Cure(ga/raga), and some attack spell for range purposes / phy. resistant enemies. Those are your 6 slots, so no room for anything too fancy, but Zack's physicals seem better than the fancier other options anyway. However. The game becomes deliriously hard again in the final dungeon - OHKOing randoms if you don't have Barrier up, and minibosses that like to toss out 8,000 damage Flares, etc. But most importantly, the problem is that Zack has been stuck at 9999 HP for some time now. It's nice that I only need 1 HP+ materia now which frees up a materia slot, but without the ability to uber Zack's HP, there's just no margin for error, and huge HP enemies means you need to stay perfect for awhile. Plus (M)Barrier can't be refreshed before it runs out; it's fine if I just have to notice that Zack is taking more damage, better recast, but in the final dungeon it becomes "watch for when the array of rotating statuses starts skipping the two since a slip can be deadly."
So. Before this I'd have said that Sephiroth was the toughest boss, and he was pretty good. 2 Game Overs on him, and that fight was suitably awesome. His Draw Slash if unevaded / not blocked does 7500 damage or so pre-Barrier, and you can get mobbed by the crystals easily enough - especially if you're foolish enough not to equip a Dragon Armlet. He'll also resummon the crystals if you dawdle after killing them, and Heartless Angel->quick slash was death the first time he pulled that on me. Still, he's doable enough. Hollander was annoying, but much like the Shinra grunts, he can be handled via massive Death spam on his worms and chugging Ethers like a druggy.
So. What is the actual toughest boss? Well, to make the final dungeon easier, I started farming Missions, but I was hitting something of a wall there too - the same "the damage is too high" problem. There was only one solution: Find myself the accessory that removes the HP cap, and make all these other fights doable again. There's a set of missions that hand out various "break X limit" items, and it was clear that the last of them would be the HP limit one. Here's the boss fight:
1 G Paladin
2 Belzecues
The G Paladin is actually fairly wussy alone - good HP but he's EASILY stun-locked and can be slaughtered one-on-one no problem. If you ignore him, he will Wall himself (good taste), has a Combo Attack if you somehow get stuck next to him and let him hit you, and will shoot his Gunblade at you (requires that you either be close to him and strafing to dodge, or else use an actual roll-dodge). Energy is a ranged shot similar to Gunblade but more damage, but also more setup time to disrupt him. And oh yes. He has DISPEL. So no more Barrier / MBarrier for Zack in a game which basically revolves around getting a good defensive setup going.
The Belzecues are doggies. Fast doggies - they zoom around the field - but fairly frail. It only takes about ~8 castings of Hell Thundaga to kill them, or 3 full Zack physical combos from behind with auto-crits to off 'em. Theoretically they can be ID'd as well - when I tried equipping Death, I got "Miss" rather than "Guarded" on them, but we're talking 0/40 batting average here. However they *bring the pain*. 3200 damage a hit, and they generally have a two-hit combo (though if you roll early, what'll often times happen is the first will miss but the second hits). And they have a HIGH CRITICAL RATE. Not sure what exactly but it's at least 20%. So yeah, a crit will do ~6500 damage (if Barrier is not up) when Zack's HP is capped at 9999. And a two-hit combo with one a crit will do 9500 damage. Lastly, they've got Disenchanting Tentacle, which is two hits of extreme overkill MP damage - like 1500 MP damage when Zack has ~300-350 max MP. Like the normal physical it's two hit and the last hit has a wide swath, so once again mistiming a dodge means that you might evade hit #1, but kiss your MP goodbye on the second hit. And oh yes, if you're thinking about, say, trying to free up some Accessory slots by getting rid of your Headband for say +60 Vit on Defense (not that Vit seems to do a whole lot in this game) their attacks Stun Zack as well, and needless to say Stun is still pretty much Zack's death warrant.
You can see how this goes. Zack gets chased by evil doggies around the field while the G Paladin dispels Zack's defensive buffs and snipes him. Pretty much any kind of hit tends to require healing to be safe, and you can only recast Wall so fast, and you can't safely stand still to cast a spell if doggies are currently chasing you. And oh yes random criticals of doom, often hitting right after a Dispel. If you aren't having enough fun running around trying to keep up you also get to toss an Ether if you let Zack get hit by a Disenchanting Tentacle.
Well. My new apartment does not have a washer / dryer, so it was laundromat time yesterday. It was also time to beat this damn fight so that all the other fights can become doable. It took about 12 deaths, but it's finaaaaaaally over. Think I might have gotten lucky on a Hell Thundaga ID somewhere? The Belzecue presence definitely seemed less than it should have, and I stayed as far away as possible while zapping with Hell Thundaga. The G Paladin got a zap if I could target him and saw him prepping Dispel, but was otherwise ignored. Eventually I took advantage of the Dogs bad durability, and once they were dead the fight's cake. But man. So much slow loading of mission, Zack hugging walls, then Zack taking a nap like 30-45 seconds into the fight. I even went to the trouble of buying the Healing Wave materia by the end and equipping it, since Aeris would also make the fight cake thanks to cheaty invincibility, but alas it didn't kick in even with the materia equipped.
Final setup for that fight:
Wall
HP++ (+520%)
Curaga
Healing Wave (boost DMW chance of Aeris)
Hell Thundaga
Status Ward
Now the game will cry as Zack's HP has now jumped from 9999 to 20,000 (swapped Healing Wave for another HP++), AND Zack's HP can get even better than that again thanks to overhealing limits. Woo.