Sephiroth have Black Materia and he'll win with his big meteor.
Squall have a gunblade and he'll lose with his emo face.

Sephiroth:
Supernova
Heartless Angel
Masamune
Black Clothes
Craaaaaaaaaaaaaaaaaaazy

Squall:
Lionheart
Lionheart
Silver Clothes
EEEEEEEEEEEEEEEEEEEEEEEEEEMMMMMMMMMMMMOOOOOOOOOOOOO

I hate both of them....

But story-wise, Sephiroth.