..So she joined him willingly...after he arranged the murder of her family...then drugged her (good drugs? bad drugs? both, so her born super got better plus yummy love-your-daddy mind control drug?)..under the influence of which she gouged her own eye out...then forgets she did it...then blames him for pushing her into it (which, he kinda has manipulated her toward) and quits him so she can fight him.
Ladies and gentlemen, this is a screwed up background. Bonus for Xanatos Gambit if its revealed later that he and she deliberately screwed with her mind to make her a Titan.