you, a normal person who likes to have fun: vriska would not be a slytherin. she has all of the traits and flaws of a gryffindor
me, jacked up on 20 years of harry potter and 8 years of homestuck meta: you’re right 100%, but the thing about harry potter and the hogwarts houses is that they weren’t decided by personality traits alone. slytherin was a house made up mostly of purebloods and rich old world wizards, and being much like the other houses was a bit of a tradition carried on throughout generations. politics in harry potter weren’t very well thought out — if a character was evil they were almost always a slytherin, which also meant they were rich and racist like, collectively. with that being said — if you align the harry potter caste system with the trolls’ caste system and actually interpret the stories and backgrounds of each characters in terms of the potterverse, it only makes sense for eridan, gamzee, equius, and vriska to all be in slytherin, as it aligns with their social position and values. vriska would probably be a figure not unlike draco malfoy, whose unfortunate birthright and cruel family forced her hand into becoming a monster. by actual definition vriska isn’t a slytherin, because she’s not very cunning and what have you, but when interpreting her story into the potterverse it fits best to put her in slytherin. within the narrative of homestuck she was a victim of parental abuse and abuse caused by her placement in the caste system of her society that took away her agency and made her a child soldier — the only real way to transplant a character like hers without stripping away key parts of her personality is by putting her in a similar social setting