Nah
He scared of them more than he care
Thats my point ig, he didn't "fix" anything bc they didn't get proper love and care they need to get better. She literally misunderstood that she took her not to be a weapon but to have a normal life like its not his fault she is delulu but if he was there for them and not hiding maybe they would've some sort of normal like but thats kinda hard to say bc they still would've been doing it behind his back
I think he does care for them but it's justified that he's scared of them. He lets them be in an environment in which they had gotten love. And he himself tried to be caring in the letters since he was scared of them killing him.
And I don't think they would have become normal. That girl was already broken to the point where she saw every message as a weapon. The problem is that all 5 of them manipulated themselves to think they are weapons. Him coming to them would have probably just make it worse or even kill him since he wasn't their ideal
I would say that mc cares for them but he could've atleast visited few times. Like maybe it wouldn't be that big of a misunderstanding