Karly and D.O.'s Past - S1.E9

As D.O's mask is taken off by Karly's spell, Karly realizes that D.O. is her old student, 'Dominic'. D.O. tells the story of his past being abused by Karly at the magic school and tells her that he has become a evil wizard because of her. Karly insists that she didn't mean it, but D.O, mind full of revenge, attacks Karly.