Aeon Darknight was a Magus of the Lancetide chapter of The Arcane Institute, working from The Lucid Spire.
In 549UN (4147), he hired a group of adventurers to prevent an artefact from falling into the hands of a cult. He later turned out to be from the cult he claimed to be fighting, and stole the artefact from the group, nearly killing Arianah Trudeau.
The Hag Wranglers eventually caught up with Aeon on the island of Lehen Kartzela, fighting and killing him before he could raise the elder god, Katuasakona.