Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 404: Defense Specialization and Blue Light 2.

The female protagonist of this book is a zombie (probably!) The male protagonist of this book is an air (maybe, but you can’t see it?) The system of this book is a bastard (like to open a mouth too much?) Anyway, this is a story about zombie with a memory, going back to the past, but accidentally turning this book into a story of a savior! (Huh? What? There is a killer? No, believe the author, she really did not kill, really! (No wonder!)

The heroine said: The title of the book and so on are all fake!

- Description from Novelupdates

The empire has turned into the land of the undead due to a spell gone wrong. God summoned heroes from countless worlds to purify the empire and plant new hope. Lee Shin Woo, an ordinary earthling, was also summoned. As an undead, that is.

A rich young master, a hedonist, has the Hedonist Sovereign System forced upon him. Follow this hedonist on his adventure of becoming a Hedonist Sovereign through doing real life quests, filled with action-packed battles and hilarious moments. A lazy and slothful hedonist doing exercise in the morning? A spoilt and self-entitled hedonist starting from the bottom as a salesperson? Watch as Qin Feng is changed by the Hedonist Sovereign System, inside and out!

- Description from Novelupdates

Tang Feng had been just an ordinary milk tea shop employee before one day, the lady boss called him to her room, and he learned what “hidden rules” really meant...