I'm going to reach out to my ex through linkedin
I'm curious if you think that's a good idea? Won't he become angry?
Yes, but I don't care. He has already battered me too much in life.
If your ex was abusive then you should stay away from them. He could become more violent if you look him up online.
I'm going to blackmail him with my skills and he will pay $10,000 to me.
You're not going to make the money, and not only that but this is just keeping you in contact with an ex that has hurt you for so long. It would be a lot better if you just moved on and found more success than he has, it is really the best revenge.