Never ask people to roast you without makeup on. Otherwise your asking for people to make fun of that. Also, never ask people to roast you with makeup on, because you're asking for people to make fun of that, too. Also, never ask to be roasted?
Don't cosplay as your favorite Game of Thrones character. Cosplay as the actress who plays her. Or better yet, maybe cosplay as one of the executive producers of Game of Thrones or perhaps the gaffer on Game of Thrones? It's much more original!