Legend of Mortal stars an unlikely protagonist– a third-rate civilian from a sector named Tang-Man. He "has no plot armor" and has a very difficult life full of hardships and misfortune. He lives in a very troubled time where threats from enemies appear at the doorsteps of Tang-Man, and he has to make constant moral choices of whether, even as a nobody, should he stand up and fight for and defend Tang-Man and help make it flourish, or continue being a background civilian in submerged in obscurity?