So-named on TV Tropes for one of its most frequent victims, a new character appears and flattens a character who is reputedly a badass to prove how dangerous they are. It happens to Worf enough that his badass-ness looks pretty questionable, but used occasionally it can be pretty effective.
But generally not on player characters.
Where a PC is built to be really good at something, there's a good chance (not 100%, but good) that the player will be annoyed if someone trumps them in it. They'll go after the offending NPC and pour any roll-boosting resources they have into hammering them into the ground.
So maybe ask first. "Is it cool if Ubervillain knocks out Brickman?"
Having a new threat demolish an enemy they've had trouble with can work as effectively and doesn't step on the PCs' personal shticks.