Arvarnaa

Arvarnaa can turn themselves, and whatever objects and clothes they're wearing or holding into a pure white or pure black silhouette. This makes their motions vaguer, and it's harder to tell what Arvarnaa is holding. This quirk is also good for sneaking in very bright or dark places. However, Arvarnaa stands out if the area isn't very bright or dark. The vagueness can put allies at a disadvantage.

W.I.P. Lemme add GeroGero's backstory before I touch this.

"Arvarnaa? Definitely an interesting person. At first, I found them to be intimidating since their expressions and posture were unreadable most of the time. Ah, but I believe that we've warmed up to each other quite nicely. We do stretches together every morning before class. They've kept things hidden for me on numerous occasions, and I help them with socializing with the other students. I think that they need me more than I need them; I'm the only one who can understand what they're trying to say most of the time. Most of the other students think they're weird. I doubt that Arvarnaa would even be able to make friends without me."

-Go Gerogero