HELP!

So... I'm hoping to go to London Comicon/MCM next month and, of course, the traditional thing is to cosplay but I have no idea who/what I should dress up as.

Help!
If you have any ideas, tweet me. I don't have very long to come up with a costume concept. I'm seriously contemplating a Cersei Lannister costume but if it's going to be as warm as it is now I'm gonna sweat like Balon's balls. If you have any ideas let me know.