....Well I'm interested to see how THIS gets resolved. Do we have a Deus Ex Medicine Machina where if we feed a bunch of money into it, it spits out a cure?
I'm kinda betting that the Monster's girl is already dead. More exactly she was killed when he transformed for the first time and either forgot about it because of him becoming a monster or the trauma of it. Or he might have just not realized that she was there at the time.