Arkus was a longtime friend and adventuring companion of the warrior Devian, and their exploits were self-proclaimed legends.
Arkus was a member of the party that led the assault against the demon plane of Shaddonon; and afterwards he was uncharacteristically quiet about the details of adventure. Like all who went on that ill-fated expedition, Arkus was severely touched, he became a drunkard and some say even mad after his return.
But the one fact he did proclaim to all was that Devian was still alive and would one day return to exact his vengeance against those who betrayed them.
No one knows what finally happened to Arkus. He became obsessed with waking the Eternal Dragon sleeping within the world by finding the master tune of waking. He set out to the mainland to do just that and never returned. It can be assumed that he was not successful since it is generally agreed that waking the Eternal Dragon will destroy the world.