The Ur-Daemons were believed to be some form of inter-dimensional beings and it was they who opened the portal to Elanthia. Destructive beings who fed on mana (and essentially, life energy), they immediately clashed with the Drakes in a devastating war of titanic proportions. The very shape of the continent was altered by the massive battles. Purportedly, only one arkati of those who fought on the side of the drakes survived, that being Kai.
In the end, the Ur-Daemons were pushed back through the portal and banished from Elanthia. It came at high cost to the Drakes, who had nearly been wiped out. This in turn opened the door for the arkati to ascend as the dominant rulers of Elanthia. The dark god, Marlu, was rumored to have been an Ur-Daemon stranded in Elanthia after the war. Likewise, the king of the arkati, Koar, was rumored to be one of the last drakes.