Maria, Mizuki, Andromeda, Scillia, Grimm, Annie, Axel, Ryuu, Rain, Caelus, and NK's villains can all use Nox.
Why can Rain use it? :S She isn't cursed, is of a generally neutral standing and manipulates light more than darkness. Turning into a werewolf isn't a curse and when she changes she doesn't turn evil per say, she just falls into a feral state of mind > "In some cases, the user's mind descends so far into the feral rage that, mentally, they are little more than animals." Sorry should have explained it better, check out this wiki > Feral Mind. Plus she's a descendent of a celestial being ^^ Her powers are (hopefully) going to develop towards that.
All of that aside, she'd be more interested in a water sword if there was one <.<
Crash on the other hand would fit in with the Nox requirements, although he's a 'good' guy so to speak he's possessed/cursed by the dark spirit of the Wendigo. A carnivorous demonic spirit.