Do you think Kirei healed Aoi after Kariya strangled her? I think we were all pretty surprised to see she survived that, then I remembered there was a master healer nearby.
Do you think he did so only so he could enjoy watching an 8 year old try to take care of her brain damaged crippled mother? Corollary; Do you think he COULD have healed her completely if he had acted quickly (resuscitating before brain cells die due to lack of oxygen is key to preventing brain damage, which means speed is everything in these cases,) and deliberately chose to leave her brain damaged, to achieve said joy?
It would fit rather well with his actions of healing Kariya so he could enjoy watching him suffer more.
Bonus: Do you think she remembered him saving her at all in the fogginess of her broken mind and felt a sense of gratitude towards him as her savior? He was a "family friend" after all, and officially at least was probably credited with saving her. SOMEONE after all had to have recovered her and called an ambulance to take her to the hospital or whatever she was between her strangulation and the last EPP. And I doubt Kirei would want random members of the public finding dead and unconscious bodies in his church. More likely he did it and got himself some credit.
P.S: What do you think he did with Tokiomis body?