Hello Cassie, I like you already! From your short description of yourself, I can tell you that the two of us are quite similar. Welcome to PA!!!
So, I've got three characters here. Rivah Trenton: She's the Head of the Creatures Dept at the Ministry, a Death Eater, and very intelligent when it comes to facts. Katrina-Carlotta Du Hunt: She's an infamous dark witch and assassin, soon-to-be Head of the Death Eaters, and a non-English native. (Yes, I'm a fellow Oxford Comma supporter.)
Lastly, I have my wonderful Vivianna Varnes. I figure this will be the character you're most interested in, as she's a 5th year Slytherin. Annaliese and Vivianna will make brilliant sparring partners as far as I can tell. If you'd like, they could start off as rivals. In fact, I think that could make for some very interesting threads, as the two girls seem to be pretty similar in may ways, especially when it comes to admitting that they like people and personal weaknesses. I think it would be fun for them to slowly become fond of the other, but neither want to admit it. As far as I can tell Annaliese's connection to music is similar to Vivianna's own with potions. The pair of them would make a brilliant team of liars if ever working together.
This is ridiculous, I already can't wait to plot with you. I must warn you, I am on a trip right now for the next week or so, therefore how much I can get on may be sporadic. If you have any questions at all, feel free to send a Private Message to any of my characters.