If he's super into the story and lore, you could get him the Destiny Grimoire Anthology

Synopsis:

Until now, the myths, mysteries, and machinations of the Destiny universe were found hidden throughout the worlds – enticing threads that hinted at a greater tapestry. The Destiny Grimoire Anthology weaves tales from multiple sources together for the first time, casting new light on Destiny’s most legendary heroes, infamous villains, and their greatest moments of triumph and tragedy.

Each unique volume intends to illuminate a facet of the world, and the complete anthology will confirm and challenge players’ thoughts and assumptions on what it means to be a Guardian, offering new and differing perspectives on the cosmic war that rages between the Traveler and its ancient enemies.