Ah. You like to look cool, don't you, Hierophant-kun? I understand. It's fine to look the way that makes you feel satisfied, even if no one will ever see it but yourself. Girls paint their toenails even if they're only ever going to keep them in their shoes, so I think you should wear a mask if you like it.

[Not that she gets any say whatsoever in how he looks or otherwise, but she's trying to offer amends for scaring him earlier, so...maybe being supportive of the invisible green eldritch creature (in a mask) is the right way to go.]

Is that why you would up with an emerald gemstone, do you think? Because of Hierophant's color?