I'm going to ruin my ex's life
You gotta be kidding. What is the point of doing this to your ex?
She hurt me and she deserves to be hurt and ruined
Your ex should already be behind you, and there is no need in reintegrating yourself into her life. No matter what she deserves, you are only going to feel better when you move past her. Trying to ruin her life is just going to have your mind thinking of her more often.
I'm going to ruin her life full stop.
I'm just trying to say to you that it may be a better idea to just let bygones be bygones. It's more healthy to move forward and look to the future, wouldn't you want to finally find someone you're compatible with? You never know if they're in front of you!