The Brain Battle is first learned in Destroy All Humans! 2. Instead of just disguising himself as a human, Crypto goes up to a human to commence the Brain Battle in order to Body Snatch them. There is a beam of red or blue light. the blue is Crypto's and the red is the humans. If the blue wins, then the Brain Battle is complete and Crypto Body Snatches them. If the red wins, then you have to start the Brain Battle over again. Inside the human, you have a limited time to be inside of them until their health depletes and the body dies, but Crypto comes out good as new. Plus, you can sprint while in a body.