Not a futa, btw. Keyaru can't completely change gender, so the technical term would be newhalf(naturally male, but changed to female, save for the penis).
@gaigous it was clearly mentioned that there's a limit to his Transformation Heal. He cannot turn dwarves into giants and vice versa, same goes for the genders.
At most he can restructure the boneframes, fat and muscles to change the appearance of the target.