"Human" is only a way of describing a person who is born naturally and mortal, in my world. There are some who think they surpass humanity by being something else, but others seek humanity. A dead person must be transmuted to become something else. A distorted and stripped version of their former selves.

[He hesitates for a moment.]

That is how the homunculi came into existence. Lust, and the people she calls her siblings. Their nature is not their doing.