Jericho The Darkstar

Jericho the Darkstar was once a mortal from another plane who attained power rivalling godhood. He lead the invading forces of the Darkstar Dynasty during the Astral Incursion. He was forewarned to Resa by the dragonborn whose plane had been conquered by The Darkstar. They warned he had conquered and enslaved many planes and was intending to do the same with Resa.
In the current day, the common person views him as a boogieman and speak of him in hushed tones, if at all. Not much is known of the real man besides he was a brilliant tactician who wielded great magic.