He'll be becoming a Vorevak for a bit. So, chances are that a mission will be popping up from the Elders wanting members to hunt him down. So don't worry, you'll have an opportunity in time to assist in bringing him back to the Order.
That's why I am glad my character kind of has got himself a apprentice so they both can try to smack some sense into Ar'Rhan but anyway can't wait to see how his story progress have fun with it