Here's an excerpt from the creative team's world guide:
The human biomancer Vorel was formerly the leader of a small Gruul clan. But when he gave the order to concede territory to a growing Boros garrison in order to secure his own clan’s turf, the clan turned on him. He was nearly killed before escaping.
Vorel of the Hull Clade | Art by Mike Bierek
The entry goes on to describe the fact that Vorel, as a member of the Gruul, was a shaman of sorts. He brought these skills and the mindset to the Simic, discovering that his strategic mind actually lent itself well to being a member of the Simic rather than the Gruul. He wasn't a perfect fit for the guild, though; his emotionally charged background still shines through from time to time, leading him to be a bit more emotionally driven than others in the Combine.
How will he fare in the Implicit Maze? You'll have to wait to find out!