Harry Potter and the Darkness Within

AU. After killing the father of the infant Harry Potter, Lord Voldemort unearthed an entity of such hatred that it made him flee in terror. As the years went by, Severus Snape became his new legal guardian, and was sworn to secrecy by Albus Dumbledore. Thinking Severus to be his biological father, Harry grew up inheriting Severus passion for alchemy. But darker days are coming.