Ho okay! Shiro likes Castor. She's a pretty solid individual who mostly is what you see what you get. Hoo boy does the whole tempering thing feel fucked up and she has his respect for how much she has had to shoulder just from that alone. She will be asked questions, very gently so.

But he trusts her to watch his back while he keeps an eye on hers and can direct people in battle. He sees her as a friend he can both rely on and also to help through this world feels like hers but isn't.

He'll do what he can for her and remind her she's not alone.