I spent ages feeling really angry and resentful towards him but it never helped. It just made me unhappy. I don't think anybody needs to punish him. He seems to be determined to destroy himself. My sister still lives in the area and every so often I get an update on how he's doing. I know it's mean but I do get some pleasure out of finding out how bad his life is.
Every time you see someone try to be an asshole to you,
with no reason, it shows you the true state of their self esteem....and that knowledge can give you power.
That doesn't mean you have to take advantage of it, but once you understand people's deeper motivations, and not take their shitty comments and actions on board as a reflection of yourself, life seems to get a bit simpler.
That's not to say it isn't easy. But you will become better at recognising it for what it is over time.
I think the fact his life has fucked up is evidence of his very low self esteem and inability to take control of his life, so he deflects shit onto others to make himself feel better.