9. Melisandre

Stannis Baratheon's fire priestess does everything for the Lord of Light. Even if you don't believe in him, you had best start when you're around her. Aside from being immune to poison and having the ability to birth shadow assassins, the red-haired sorceress also has a habit of burning people alive in sacrifice to her god. Even if you secretly think her religion is a bunch of crap, she'd probably know. Yeah, you're screwed.