”...what are some crazy or evil ways of getting revenge?”
Ignore them. Just completely ignore him, as if he doesn’t exist.
Human nature 101 tells us that people want what they cannot have. You may not think it’s working, but I assure you child, it will drive him crazy mad to discover that he has absolutely no affect upon your mind and emotions any longer. He will know that you are responsible for this pain he endures. Just ignore him. Banish him to solitary confinement, the worst sort of imprisonment.
This is a good evil crazy plan. Because while he’s fainting over his inability to get your attention, you are getting your own head on straight and becoming a better person who doesn’t need to satisfy her immature desire for revenge. I wouldn’t want to date a girl like that either.