Your top five boss battles in gaming, one per franchise

[RenCutypoison]

1) Riku (Kingdom Hearts)
2) Kefka (FFVI)
3) Persona 3's Final Boss
4) Biggest post-game Boss (Disgaea 5)
5) Simone (Nier Automata)

All of them except D5's one are because of their plot implications and/or design. I don't care much about bosses gameplay.