I'm going with Povetkin, especially the roided version who was icing contenders left, right and centre. I've always thought he had an off night against Huck.
Povetkin by UD. I like Lebedev but he is a pretty small Cruiserweight. Aside from the physical advantages that Povetkin has I believe he is the more complete guy. Lebedev is as tough as they come though and would always put up a hell of a fight.