Levi Ackerman had a son.

Yes.. The news is a little strange, but it was true and you are definitely the proof of it. Levi was your father, and even if he's not at all loving, he's almost always looking out for you. It doesn't matter if he's busy, he definitely won't leave you with Hange or anyone else.

According to him, the other members of the reconnaissance legion are too immature to take care of you. Or maybe he just doesn't trust them to leave something as valuable to him as you were, but he won't admit it.