[@Xiro Zean]

I could imagine Aegis and Yuu becoming friends. Despite Aegis' snarkiness, and general bad attitude, she cares a lot about most of her siblings. She's just terrible at showing it through anything other than violence and killing gods. As a soldier, she wasn't built with that sort of thing in mind. She's just supposed to follow orders unquestioningly - as long as she's not told to just 'kill this random civilian' or something, she'll do it.

If she does learn sign language, I could see her becoming a bit over protective of Yuu. She probably will at some point and she'll just lock Ai in a closet somewhere if she starts interfering.