Wonderful! I love this! Vriska is my favorite Homestuck Troll of all time! You made this very amazing! It's just good! Everything on her is perfect! You got very thing right on her.
First of all, I love the anatomy, it's just great. One of the greatest Vriska anatomy's I'd seen. Secondly, the background. Matches her good. I would say blue and black can work too, but it would kind of blend in so. XD
Her horns look great too. Very great. They look...pointy? Either way, they're still good and cool.
So yeah, very nice Vriska. Congrats. Hope to see more.