People like him are like half machine and half feral animal. They don't really enjoy much of anything and covet what emotionally healthy people have, while never actually understanding it. They are wretched, gnashing things who live in endless boredom and agitation. Even your pity is wasted on them because it has no effect on them. And so is your hatred. If a tornado blew your house away, would you hate that tornado? Would you spend your years hating the sky? Probably not, because the sky doesn't feel. Well neither does your ex. Sociopaths are tragedies and we can all agree that often the circumstances leading to the creation of a sociopath are horrendous and unacceptable. But it still is what it is. You must allow yourself to see him for what he is. A machine. A tornado. A virus. Not something that is worthy of your emotional energy.