The Horcruxes are Voldemort; beings with little soul willing to kill to achieve success. In Harry Potter, there lies one of these beings. Harry Potter, the one supposedly prophesied to bring about the downfall of these very fragments, is a Horcrux. They are alive. They are all alive. And they have schemes so horrible, you cannot comprehend them.

Harry Potter's mother's love defeated Voldemort. So it stands to reason it would defend him against the soul fragment. But that particular ritual was not used anymore for a reason. Tom Riddle is stuck inside Harry's head. And has been raising him for all his life. And plotting global domination. Of course Harry wants to be Overlord! Why shouldn't he?