[He can't let this orgy of self-blame occur, not on his watch. So he bends his head down a bit to meet her at eye level.]

Absolutely not, Kaname. First, the past is the past and can't be changed. Second, you didn't know and you couldn't have understood. Third, if she took you in, it was a risk she chose knowingly. You don't need to assign fault to anyone, but if you assign it to yourself, be sure to apportion it in proper amounts to everyone.