I was looking across some writing advice while I worked on my yuletide (about 8,500 words and nearly done now), and found this little gem on writing villains:

Nevertheless we mustn't forget that our villains are sometimes related to the hero or heroine. Tricky balance here because we are all aware of hereditary factors in human beings. The danger can be that doubt is built about the hero or heroine's ability to be heroic when they have such "bad" blood flowing in their veins.

To heck with you, lady. I ain't finishing this.