"In my game analee's fiance had robbed the party causing the them to send the hand to kill him and retrieve what was stolen. there is then a time jump and the party meets christhia. she tells them about her story (but says she doesn't know the name or look of the killer) and joins them on the rest of there quest. when the group returns to there safe house they meet the hand expecting to be paid. the party wanted to hear the story, proof that he's dead and there treasure back. the hand returned the treasure and told the story (which matched christias background). he finishes by pulling two heads out of his bag as proof which causes christia to loose her mind. the game ended with the party choosing either to help one or the other in a fight to the death."
This is just one of many different situations that these villains can fit into. If you need a villain for a story you've already started then its easy to implement these characters. However with everything given its more rewarding to just run with there backstory. All in All this was great and very useful. 10/10 would recommend.
[5 of 5 Stars!]