Hyperion

Hyperion was one of the Greater Titans who was imprisoned by the Olympian pantheon in the plane of Carceri. Just as all Titans were said to have dominion over some form of building block of the Prime Material, Hyperion held dominion over suns.

History
At some point in the late 14 century DR, an adventuring party somehow ended up in the Othrys layer of Carceri. There one of them, a paladin by the name of Uri, would end up a captive of the Greater Titans after his fellow paladin Elendil cowardly fled from the scene. Uri spent the last days of his life in captivity, held in a tower on Mount Othrys and forced to engage in gladiatorial entertainment for the amusement of Hyperion.

In the month of Hammer, in the, a group of adventurers from Ravens Bluff found themselves transported to the plane of Carceri after defending the githzerai fortress of Tah'Darr from a tanar'ri incursion. At the urgings of Elendil, the adventurers learned of Uri and sought out the Titan Cronus for a way back to Toril. They traveled together to Mount Othrys, with Elendil having last heard that Uri was recently involved in combat with tanar'ri. They eventually made to the crumbling palace of the Titans and inside Cronus informed Elendil that his colleague had been killed and eaten by visiting tanar'ri.