Emrys Ascending (слэш)

In the depths of the Crystal of Neahtid, Merlin sees the resurrection of Lord Voldemort, an event that will tip the balance of the world so far out that only he has the power to intervene and set it right, or stop it from ever happening. For that, he'll have to pose as a student and attend Hogwarts School of Witchcraft and Wizardry.
The only problem is, he's been chosen instead of Cedric Diggory as a Triwizard Champion, and there's a recently reborn Arthur Pendragon in Gryffindor House.