I would say collaborate slightly, so as not to give too much away of your arc, with books as far as the arc goes. If he is fighting for control, its going to take a while of struggling through it and training with the problem till it comes to a climax arc. Kinda resonates with the hollow form or the nine tails from bleach and Naruto if you ask me, just for some comparative guidelines anyway. Your character should be free to join up with us. Drax will continue to train him with Leon when its time to learn something new ;)