Sounds like to me Crow is purposefully saying those things to scare Leviathan. It makes sense to tell her his daughter was one of the victims but repeatedly telling her she has to die looks unnecessary.
He also never opened with the whole truth as if he was testing something repeatedly trying to scare with “God is watching” and the like.
I think he knows the only way to get Leviathan out is convincing it that he will kill Messiah-chan and in doing so Leviathan as well.