Dark Themed Hypesquad House

I feel like this has been suggested before, but I can't find it so here we go. The HypeSquad houses need a dark themed house added to their ranks. There isn't a good place for the chaotics to go right now. To draw a parallel between this and Harry Potter, we've got Hufflepuff (balance) Gryffindor (bravery) and Ravensclaw (brilliance), but no Slytherin! The new one could have a black badge and be given if the user were to choose chaotic or diabolical answers.