[@Rune_Alchemist]
Speaking of thoughts on siblings, I may or may not create a relationship chart for Ai and Yuu to the rest of the cast. Not entirely sure yet, but the thought is there.

Its not that Aegis would be protect ed because Yuu thinks her to be weak, but becuase she would want the two of them to stop fighting. The main reason she would stun Ai and not the other person is because other people can be reasonable. Ai, when it comes to "protecting" Yuu, is not.