[He suspects bitterness, given the way he's gotten his real emotions to crack through during this conversation. He responds, calm and gentle:]

You were raised as a human. You've never told me what you are - you certainly look like one - but perhaps you should listen more closely, to the things I define as "human". It's a perspective, it sets us apart from those who never lived as we did.

...Whatever runs through your veins, living as a human is what originally shaped you as a person. It's how you learned right from wrong, and the way the world works.