It depends on how evil you want the villain to be. Is he greedy and wants power or is it vengeance for a loved one. It all really depends on how you want the villain.

Personally I'd say, keep the villain evil enough. Vengeance, in the sight of some, justifices a lot. And if it doesn't justify it, people will at least understand and feel somewhat sypmathetic towards the villain. Which is good to a height.

Are there any other things to discuss actually? We're doing plot now and i think we did a little world building. Would there be anything else?