This doesn’t exactly fit the format, hopefully that’s ok. I’m hoping folks can help me find the examples for this one. I love this trope but haven’t been able to remember any!
Usually this happens at the end of an epic fight, the BBEG is often like stunned or something. Each team member tags in one at a time, beats the tar out of them in their own unique style, then tags out to the next team member.
The only thing that comes to mind is the Bahamut fight in Final Fantasy: Advent Children, but it’s not quite right.
I think the one you’re really looking for is Dungeons & Dragons: Honor Among Thieves. In the climax the whole party is piling on the BBG but they’re doing it using D&D’s rules of initiative so each ‘player’ gets a 6 second encounter where they get to hit the enemy and then it moves on to the next one.