A Teaspoon of Riddle

Feeling abandoned and left out to dry by his friends and comrades, Harry had a one-on-one with the piece of Voldemort lodged in his head, finding that the two of them have more in common than different. After some back and forth and a little convincing, Harry and Tom came to an agreement. They would come together and form... Tarry Rotter! ... Actually, I think just Harry Potter.