Midnight at the Oasis
Gaius was the leader of the angels on the demiplane of Samarthia, created by Heironeous as his perfect servants. He was one of the few angels who had individuality, as the majority were unthinking clones. They spent eternity fighting back and forth with the salamanders that served Heironeous’ brother Hextor.
When the beholders arrived at Samarthia, Gaius retreated into Heironeous’ throne room and sealed it off. The angels never saw him, only receiving his orders through the closed door.
The party never learned the mystery behind Gaius’ withdrawal from the world, as he was permanently killed when the plane was destroyed.