In Servitude to the Dark || Tom Riddle
When Tom Riddle, of the diary, senses the dormant horcrux in Aster's scar, the two soul fragments merge to create a phantom being named Marvolo. Marvolo is stronger than any single horcrux, but still has to depend on the diary and Aster's magic to exist. Instead of becoming enemies, Marvolo takes Aster under his wing...