Not including the optional bosses like, The Phantom, Xemnas in KH1 or like Lingering Will. Hands down it's still Demyx SFDJHK
THIS BOSS IS STILL SO STUPID @ me. THE CONCEPT IS SO ANNOYING AS WELL, like 10 seconds to defeat 70 water forms, like it's barely possible... It's a lot of like, are the forms annoying enough to dance away from you before you press triangle. THIS GOES DOWN AND ONE OF THE DUMBEST BOSS FIGHTS IN KH