In Final Fantasy 10 whose the hardest boss?

Question

Whose the hardest boss other than penance?

and what drak aeon is the hardest to beat?

Answer 1

Omega weapon was hardest "normal" boss, Dark Anima hardest Dark Aeon.

Answer 2

1.Sin is the hardest.

2.Bahamut is the hardest of the Dark Aeons IMO.

Answer 3

the last seymour battle is the hardest one to defeat.

the darkest aeon to defeat is probably anima himself (he's huge and strong).

Answer 4

the creature that looks like ultimate weapon in the moster arena.

you need to capture all the monsters to unlock it

any of its special move can one-hit kill

the hardest dark aeon is bahamut in my opinion