Everypony has their own inner demons they must fight, but for Twilight Sparkle hers is very real. After using dark magic Twilight learns of a powerful, and evil entity that has been sealed away inside of her, and now that she knows it's become active. Now she must learn to control it's power before it's power controls her, and it takes over her body.

NarutoxMLP crossover.
Credit goes to Tony_Tony_Chopper for being my proofreader, and also for giving me the awesome name.