Mind you, Don Corneo does take a large plunge and dies, (didn't think it to be too much a spoiler) but that doesn't mean he shouldn'thave a chance at old Seph, too! I mean, c'mon, if he can get Cloud in the sack, I'm sure he can have a whack at Sephiroth.

But in all seriousness, Vincent would be my pick. Like katana said, he had to "attone for his sin". Pretty good way to attone for any sin is to shoot it or turn into some sort of creepy frankstein man and shock the hell out of it.