Inside the tower you have to fight the warring triad themselves, the Goddess, Fiend and Demon. They're surprisingly easy to take down for being the source of all magic in the world, but that's only because Kefka already took most of their power. He's at the top (naturally) where he has full freedom to shoot his giant death lazer across the world at will, as witnessed personally by two of the characters early on in the second half.
All the teams meet up at the very top after traversing their own separate obstacles along 3 paths. With the best equipment and strongest spells, they should be all ready to fight the power-mad clown for the peace of the world.
On top of what seems to be a huge, floating throne of trash, Kefka greets the crowd of people who have come busting into his house shooting up the place the way most villains do: intimidation. Covering himself in a pyramid of power (likely representing the Triad), Kefka uses his power to toss party members around, declaring how they are all like insects to him and that he will destroy everything in the world. His power has led to arrogance.
Being completely insane, Kefka pushes the nihilism angle of villain motivation. He believes that everything in the world will eventually end so he might as well end it now. There's something very back-to-basics about it. It's such a stock villain motivation yet it's one we rarely see because we try to avoid such cliches. Now that it's so rare it feels more original here.
Kefka does not like this clash of ideals. The hope-filled words of the heroes only upset him, and he throws a destructive fit, raking his frickin' lazer beam across the world.
The final battle at last begins after you organize your now-regrouped party members, including the order at which they'll come out. You'll need to focus your very best stuff on the ones you choose to fight because it is quite a gauntlet.
Instead of fighting you himself right away with that power he just showed off, Kefka has you ascend the giant abominable tower of doom!
This tower is one of the key reasons this final battle is so high on the list. I've simply never seen anything like it. It's expected for final bosses to be huge, but this is literally a giant monument. Each of its 3 sections dwarfs the main cast, all the creepy bodies coming out of it are in Kefka's image, pipes full of steam (or magic discharge) pour out like in Kefka's tower and the attention to detail of it all is exquisite.
It's also one huge reference to Dante Alighieri's epic poem The Divine Comedy, which is not actually a comedy, but the title of the work being referenced was likely meant to cleverly play into Kefka being a clown with divine power.
Each section is like its own smaller multi-segmented boss, leading up to the strongest one as you go higher with each one's defeat. Thankfully the game allows you to utilize most, if not all, of the party you have, as when you move on to the next section of the tower, any dead allies are removed and replaced, if you have any more to spare.
Phase 1It starts with the demon on the bottom, composed of two hands and its head. The hands deal powerful physical damage while the head can cast spells like Protect, Dread Gaze and Reverse Polarity, which switches the rows in your party's formation. The head starts out rather lax at first, but starts getting aggressive as it takes damage, which you would think means you should get the hands out of the way before picking a fight with it, but killing it last makes it self-destruct with the very powerful spell Quake.
|What am I looking at?|
|"What's the matter kids, don't you like clowns?"|
|"Don't we make ya laugh? Aren't we fuckin' funnyyyyyy?"|
|"You'd best come up with an answer cuz this thing is going to explode in a few turns, and if you ain't got a reason why you hate clowns, I'm gonna kill your whole fuckin' party."|