The Librarian of St. Bright Tower

Vahlen dreams of being a magician at St. Bright Tower—the greatest institute of magic in the Paula Empire. Too bad he's just a lowly librarian there... until one day when he stumbles upon a magical book that promises to bring him glory. Now he is caught in an endless cycle of horrific events, doomed to repeat the same days over and over unless he can manage to figure out how to save Princess Elyse and achieve his fated destiny.

(Source: Tapas)