[@Inner Demon] And my above post is my reasoning for if Beast and Miyu did bond, what would happen would be:

BEAST: Am I a good protector robot dog who mistook you for my owner?

Miyu: Yes you are! Wanna play fetch? And then go look at one of those stars up close so I can try to solve my question without having to overcome my bizarre fear of talking to Ciel?

BEAST: OH BOY OH BOY!

And they'd never actually go fight. I think we'd be doing a 1 on 1 roleplay where a GM occasionally comes in and says "And here's the name of the god/beast/giant snake that is responsible for that interesting phenomenon."