Chaos (Dragonlance)

Chaos was a primal deity, first child of the High God, who rebelled against his father. Defeated, he went mad and was trapped in the Graygem. He was unintentionally freed by the Irda when they broke open the Graygem, and immediately began efforts to destroy Krynn in what became known as the Summer of Chaos. Much destruction was caused and lives lost, but Chaos was ultimately beaten by a combined effort including both the Knights of Solamnia and the Knights of Takhisis. "Paladine" (actually Takhisis in disguise) ensured the banishment of Chaos by severing Krynn's ties to the other gods and magic (setting the planet adrift in the Ethereal Plane).