Io

Io is one of the Elder Gods who existed during the Blue Age. They were cleaved in two by the primordial Siosivash, forming the twin gods Bahamut and Tiamat. This action started the millennia-long war known as the Dawn War.
It is rumored that a fragment of Io's divine essence splintered off when they were cut in two. This artifact has been highly sought after by many would-be conquerors throughout history, including Kaplan Hess, the endling. This search in fact sparked the series of conflicts known as the Crown Wars, which lasted over 800 years, and ended with the Mintici Compact.