Because I didn't clearly remember the character's name in Fight Club, this made me initially think of kind of a superposition of Brad Pitt as Tyler in Fight Club and as Chad the personal trainer in https://en.wikipedia.org/wiki/Burn_After_Reading.

"Pitt...said when he was shown the script, he told the Coens he did not know how to play the part because the character was such an idiot: "There was a pause, and then Joel goes...'You'll be fine'."