Pro tip: a waiter in Boise told me my villain had no reason to be evil, and it fixed my whole story
He said a bad guy who is just bad is boring, so give him one small want that makes sense to somebody. What's the smallest want you've ever given a villain that suddenly made them click?
Worked at a pizza place in college where the owner would yell at us over the smallest stuff, like a box being folded wrong. Everybody hated him until his wife left and we found out the shop was all he had left. He wasn't evil, just scared of losing the one thing that still made sense to him. I stole that for a villain years later and it worked better than any big motive I ever wrote. Give a bad guy one small thing he can't stand to lose and people will get him right away.