I had that same thought. I do love the chaos of the wild magic, and it fits quite well with how the Verdan came to be. My other thought was an Undying Warlock. I don't know much about That-Which-Endures, and couldn't find much, but it sounds Undying. Given that plus the Verdan's unknown age limit, it seemed to fit. After all, who doesn't want to hire an employee that has trouble staying dead?