Nix is a boss in Final Fantasy XIII. She is half of Snow Villiers's Eidolon, and she is fought in Lake Bresha, along with Stiria, by Snow, as a test to prove his strength to them. They first appear when Snow is threatened by oncoming PSICOM troops, and save him from them, before the Eidolon turns on Snow. Along with Stiria, they make up the Shiva Sisters. Once the Shiva Sisters have been defeated, they enter Gestalt Mode, and become a motorcycle.