TLCW (True love Crossing Worlds)

Armed with memories, knowledge, power, with the promise of allies, and his true love at his side, Ares Pendragon (formerly Harry Potter), goes back to the end of his second year. So he can do the most good, save the most lives. His soulmate Mal, originally not from his world, is at his side, and together, they embark on the task of saving, not just that world, but the universe.