I just realized that not too many anime villains are believable. I mean, henchmen or not just look at Code Geass. "LET'S KILL INNOCENT CIVILIANS BECAUSE WE CAN!"
Any villains come to mind that can justify their villainy? I think that Princess Mononoke does a good job at making their 'villains' believable and Light Yagami I could probably see walking on the street.
Hope he doesn't mind the bus of orphans I blew up the other day.