It was a strange feeling. One moment Darren was full of mad drunken power, and the next, his memory was wiped from his friends and family, and he was literally being drank by the stranger in the corner. Barnibus wasn't drunk on power like Darren had been, Barnibus was power incarnate.
He lived a secret life of power, and he had seen into Darren's mind; he saw the crude and base impulses going through Darren's mind, and knew immediately that all who were in Darren's life were in danger. It was sad that so many people wasted the gift that Barnibus gave them. They had silly notions of why they came into power, or just simply didn't question it and started using it to abase and abuse people. Barnibus decided to intervene more than he normally did in this case.
Not only would he take the power, but the images in Darren's mind were so disgraceful that Barnibus decided to take Darren too. In an instant he had erased Darren's existance, translating the power-hungry boy into liquid form in Barnibus' glass. He then drunk the once-youth down, and Darren became Barnibus' asshole. Literally. A living, self aware asshole, with memories of who it used to be.
"What the fuck?" Barnibus heard Darren's voice in his mind.
"I'm the one who saw the power make its way to you, Darren. I saw what you were about to do with that power, instead of using it for good, and I saw that the alcohol was only an excuse - that you are a rotton asshole to your core. So I decided to make you literally an asshole, so that at least you may serve some useful function. Welcome to my ass, you shall henceforth be known as asshole, because that's what you are now. Welcome to the rest of your life."
Darren's voice flooded Barnibus' mind with rage, then in an instant, that rage was silenced. "I gave you voice, and I can take it away. For the next week, the only sounds you'll be making will be my farts." Barnibus pushed some gas out of Darren for effect. "Enjoy, asshole."