On the second though... Prospit is described as "adaptive, reactive, capricious, extroverted, intuitive" while derse is "logical, active, introverted, rebelious, self aware" Vriska isn't really prone to rebelions, her whole arc is all about her trying to get a cool important role in narrative. Nepeta? Fits the "self-aware" part of Derse purtfectly. The rebelion part can be observed in her moiralship with Equius. and her hermit like approach to society (rebelion by doing as you desire anyway).

Vriska’s rebellious attitude may not come from her relationship to the narrative itself, however she’s very active and her rebellious nature comes more to the norm, her friends and Lord English. She’s there to raise some hell, pushes her friends away before the Terezistab, is a strategist and power gamer- Her attitude certainly fits Derse more than it fits Prospit. On the other hand, Nepeta is quite capricious and extroverted, and while she does sort of push back against Equius’ refusal for her to do stuff, she still ends up going along with what he wants most of the time in the end. You could make a case for both really.