The Encyclopedia Frobizzica
Jeearr
From Sorcerer (Encyclopedia Frobizzica):
There's a long write-up in the mythology section. The evil force called Jeearr once spread pestilence and terror across many lands. Only the combined magic of many kings and wizards stopped him, even as he was preparing his final assault. He was imprisoned in the void beyond our world, his jailors warning future generations that his exile might not be permanent.