Hello and sorry to hear of your challenges. You explain the troubling circumstances of your "friend" (your quotes), but deny any qualification to "self-diagnose", even though you're talking about diagnosing your friend, not yourself. Then you ask what "a person in these circumstances do?" Whose circumstances, yours or his?

Instead of reading "What's someone to do with a young sociopath?", your post title reads "What's a young sociopath to do?"

I'm partial to this suspicion because I usually take pleasure in following an embarrassing or incriminating question with the trite disclaimer "Asking for a friend", so I must ask, are you asking about what to do about a stand-in "friend" or your own personal issues?

There's appreciable ambiguity in your post over who needs advice about who doing what. Since I owe you the respect of a straight answer, if you are indeed your sociopath "friend", then find a therapist with whom you can explore the roots of the history and behavior you described so you can stop damaging yourself and other people. If you're not the friend, watch your back and try not to end up riding shotgun on his long road to ruin.