Arturis was a celestial warrior created by Tyr, the god of justice, to eternally stand guard at Tiamat’s tomb in the celestial plane before the prime material plane even existed. He was eventually killed, resurrected as a demon, weakened, and sent to the prime material plane by another goddess, Leira.
After his exile he roamed Baricus, killing mindlessly and indiscriminately. After years of wandering, he was imprisoned by the Red Claw bandits and used as protection in their hideout.
He was finally put to rest by a group of adventurers that entered the Red Claw hideout.