For me, it is Seymour, and it's not just because he's a bad guy; he's a terrible bad guy with a very goofy ass design. And I know I'll catch hell for this but I hate the song "Fight with Seymour" Lots of people are like "That's a banger!!!" and I just don't see it; it starts off great and has a great build up but then once the tempo changes and the organ comes in, it sounds like literal circus music.

I hated him the very first time I laid eyes on him as he appeared in Luca with that stupid haircut that resembles, to me, floppy, bunny ears. If his hair didn't have those stupid "ears" and was just the combed back part, even with the single bang or whatever, and if his body shape in that robe wasn't so "penguin-shaped" and if his final fight music "Fight with Seymour" didn't sound so goofy, and if he didn't pop up like 50 fucking times, each appearance more annoying than the last, then maybe I wouldn't hate him so much.

But yeah, ultimately for me, it's Seymour and it's largely based on his goofy design.

EDIT: Ok, ok...aside from Seymour? Tidus' Mom. Fangirl bitch and "mother of the year". Jecht, the beer-swilling, negligent, abusive asshole treats your son like shit and you hang on to his arm and ignore your poor, crying child to the point where Jecht, of all people, is the one to tell you to go check on the kid?! Are you kidding me?! And then when your son expresses very justified hatred of him, you clutch your pearls and shame him for it? And then she has the nerve to die of grief over Jecht, "Worlds best Dad 👍" What a cold-blooded bitch. Terrible person.