*Suddenly, I bring a hand to my head, and groan in pain, as my eyes switch back and forth between colors* Me: Get out of my head!
Creature: Why should I? I may as well use you to kill your friends! I think I'll start with my former vessel...or maybe even my current vessel's lover? Oh, so many options!
Me: No! I won't let you! 
Creature: Try and stop me! *The creature has finally gained full control over my body and has not only reactivated my Sharingan, but also begins to attack everyone* Amaterasu! * Black flames appear a few feet away from everyone and begin surging towards them.