Responses
I think he can not use it in words. You want to cherish your love protect them not hurt them so I believe he doesn't say "love".
If we look like this he can not love. But even if it is an obsession there are feelings and let's be real they're crazy I couldn't be satisfied with to some kinda lovey dovey thing. It doesn't feel right.
I know that Moo is a psycho and even to Kirin it’s not love but it’s more of an obsession. I remember that Kirin asked him “Did you love her?” When they talked about his sister, and Moo replied something like what is love. But guys, don’t you think Moo had like a special feeling to her? Maybe not in a sexual way like he has with Kirin, but something more platonic? Moo even said that he finally had a real reason to ‘kill’.