Jester David
Hero
Yes. But also lengthy description of people and places and monsters. Descriptions of what they're doing and acting along with some sound effects.I don't watch CR so can someone explain what is distinctive about Mercer's play style that people try to emulate? Is it just the use of voices and extensive in character dialogue?
Plus, he does make interesting characters and memorable NPCs through a combination of voices and also descriptions and mannerisms. Characters the PCs want to keep interacting with.
But he's also famous for asking "how do you want to do this?" for the killing blow in a fight, asking for narrative inspiration for the ultimate strike. Which is also the signal to the players "you won."
He's also not a helpful DM at times. By which I mean he won't remind players too much of the names of an NPC or a place. He won't hold their hand on who is what with details the players should know. He pushes them to keep notes and use their memories.