I have a few characters which (In my opinion) I don't classify as "evil". Almost none of my characters are evil, but I can say that most of 'em are unstable psychopaths who enjoy a good brutal battle (And of course with good ol' sadistic humor) every once in a while. Not evil. Just, mentally unstable to the point of disembowelment. They're actually moderately normal, fun (and love dancing) but when you set them off they go berserk. The thing is, they're so nice, you'd have to be evil (or a jerk XD) to set 'em off. Whoever triggers their violent emotions usually have it coming to them.
Though, what bugs me is when people claim to be "all powerful" but when it comes down to a battle they're too afraid to drag it on, so they one shot you X'D after a good minute of fighting..I find it ironic.
I can admit, I have seen some pretty decent evil characters who have had lots of planning with their chara's which I admire.