Grayscale. They're part of my fun little superhero/supervillain AU of City that Never Sleeps. It's similar to Dr. Horrible-- it's a dramedy and is in the villain(s) POV-- but it will be following both Linus (Grayscale) and Dhaka (Hyaenidae) with darker drama and the tension in their friend group. It'll also focus on the denial, ptsd, and mistrust that forces Linus into Grayscale, as well as the bottled anger and fear that forces Dhaka into Hyaenidae. Again, this is an AU, mostly just for fun. But, it doesn't make their feelings non-canon
Grayscale (called Gray by Dhaka) is an interesting case. While Linus can choose to "transform" into them, it's usually triggered by intense feelings of mistrust, betrayal, anxiety, danger,
loneliness, fear of being forgotten, trauma, etc. Hyaenidae (called Hyena by Linus) puts the muzzle on them to keep them from putting themselves in real danger, though Gray will take it off if they need to attack.
Gray isn't exactly aware that the things they do in that form (attacking, killing (which is rare), stealing) are crimes. Their intense mistrust of others-- especially in that moment, which in they only trust three (and usually only one, Dhaka, is around)-- clouds their mind and makes them think that they are doing this to protect themselves and the one they trust.
The way Gray protects their identity isn't by their own means. It's more a magic, force-field like thing that makes anyone who knows them not even realize Linus and Gray are the same species. Gray and Linus's personality differ so much in other's minds that they think it's impossible.