Harry Potter, Demon King of Tyranny

Anos Voldigoad decides to reincarnate in a different world after becoming bored with his own world. He ends up reincarnating as Harry Potter and reawakens his memories and magic (same as beginning of his second life) when he is hit with the killing curse the first time. How will the Wizarding World deal with a Harry that is also the Demon King of Tyranny? T for now HP/HG/FD