Always had a thing for someone being transformed by their collar being popped, into a preppy/chav/frat boy. Don’t know why but maybe it could give you some inspiration?
Brian was looking around the party wondering why he bothered to show up. Alpha Gamma Phi, the schools frat invited all the freshman to a beginning of the year party. He wasn't the type to party, being a nerdy physics major, so why did he even bother coming? But before he could think about it more someone came up behind him "Brody! You made it!" Soms guy shouted, grabbing the collar of Brians shirt and popping it up, looking like the way dumb bros typically wear it. As soon as that happened his head hurt as he started forgetting physics, starting to remember taking classes in sports science. His hair started to get longer and tint a dirty blonde. His skin started to tan as muscle grew mixed in with a bit of a beer gut as the soda in his hand became a beer and he started to feel drunk as he got dumber. He started dancing and flirting with the hot sorority girls who were there. His identity shifted as he now thought of himself as Brody, the hot frat boy and sure as hell not Brian the nerd!