a mutant part of the X-men. If she touches a mutant with her bare skin, she absorbs their powers and if she holds on long enough, their life force. She doesn't actually kill people, but she puts them in a coma. Same with humans.
Rogue to Gambit, her boyfriend: "YOU KNOW WHAT HAPPENS WHEN I TOUCH SOMEBODY!! DO YOU WANNA END UP IN A COMA??"
Gambit about to kiss her: "Maybe it's worth it, no?"