I feel slightly soiled for posting here.
The question is who is more evil, kids, not who would win in a fight. In fact, I'm inclined to assume many who voted for Sephiroth did so because he's of these…these "bishi" things you PC goers seem to revere and worship (and possibly get off to). This alone makes me sad. Large Japanese weaponry and silver hair a good villain does not make.
Who is more evil? Voldemort. I am no great fan of Harry Potter, but to answer this question incorrectly would require two retarded people to procreate and spawn a child whose mind was only a dark void that obliterated any possible chance of intelligence. He MIGHT get this wrong. MIGHT.
Let's take a gander at their respective careers, shall we? Sephiroth actually helped people for the majority of his life as a top-rank SOLDIER, exterminating monsters and what-not. Only after he learns of Jenova does he turn away from this cause. But does he then wallow in the grim thoughts of pure evil? No. He is consumed by the shadows of madness. Sephiroth is far more insane than he is bad. Insane and traumatized to the point where he believes his path to be a divine course of action that must be traversed to restore balance and enact judgment. Yes, he kills some people on his way and summons a meteor to devastate the planet; evil. I'll give you that, it was VERY evil, but he did it because he thought he was doing the only right thing (helping his mother) and it was done more out of madness than anything else. Still though, I can't refute that he is actually a bad guy, just not to the degree his foe in this debate is (the fact that his final attack would have killed him as well and he knew this is enough proof).
Sephiroth is evil, but more so he was insane.
Voldemort, however, just started killing people. He created a sect that killed people. He killed people for the hell of it. Voldemort is actually the blackest of evils, where tortured screams and maimed corpses lie in his wake.
In a battle, who knows? We have no basis for comparison, since the two worlds are completely separate. For all we know, Sephiroth could dispel Avada Kedavra or whatever. I'll offer no guess to this. I'd say that if Sephiroth leaped out and whacked Voldemort, he'd easily win, but he seems to be the type who doesn't attack so deceitfully. I'm undecided here.
