Bastion, by Phil Tucker

A bestselling progression fantasy series about Scorio’s quest to rise from the ashes to conquer the ten layers of hell.

Reborn without memories, Scorio learns that he is a Great Soul, a legendary defender of the ancient city of Bastion. That within the hallowed halls of the Academy and under the stern eyes of the underworld’s greatest instructors he will enjoy enormous privilege, rediscover unique and wondrous powers, and one day return to the millennium-old battle against their infernal foes.