"No, I'm tired, and you're supposed to be asleep. You can't be here when you're recovering, especially when the situation of the crystals is terrible. Exposing yourself to them might risk your health deteriorating and I swear, I won't be able to save you if it happens," she scolds and more so than Mizuki's intimidated by her strictness, Seto stands like a golden retriever being berated by its owner.
The colour from his face has drained as if it's being directed at him, feeling awkward as he's inevitably roped into the conversation since he's the only one here with an umbrella. It's only once Grace takes a deep breath after her lecture that she notices the third person in the situation.
Mizuki has always noticed this, how each interaction happens systematically, like it's planned in some otherworldly way that's intended to never be noticed by her. She doesn't question it because knowing she's talking to false people would scare her at some point.