[Well, that's a lot of questions. He opens his mouth, closes it again to decide where to start, and then begins:]

First of all, good lord no, I didn't have babies with some poor human girl. That's on the short list of Things That Get Your Wings Ripped Off by a Superior Officer. I can't explain why the genetics work the way they do. Not my department. But my vessel's bloodline goes back almost as far as the human race.

It's possession, I suppose, but it doesn't work the same way demonic possession does. And he...well, in my own world, he should by rights be given a place to rest in Heaven, but if I'm stuck here forever... [He makes a rueful shrug. He'd be very reluctant to release Levi's soul here. Anything could happen.]