I always love these characters more when they have a dark side...doesn't it make him all the more alluring? At the same time though, realistically, would you want to be with a murderer? So in a sense...you hope he's essentially good afterall, so they have a romantic relationship...
OR
What I would prefer: hehehe, is that he should corrupt the central heroine, Lydia, in this case, and they should all live a happy, evil life