MTL - After Being Transported into a Book, I Adopted the Villain - Chapter 66

The main character is reborn as a character from a game he played in his previous life. This character falls into ruin along with the villainess, spending the last of their years together. A man named Kururi Helan.

The Grand Sovereign, Kang Chul-In. The man who was so strong that he had to be defeated. Having lost, he must now go back in time to take up the challenge of becoming supreme in the Continent of Pangaea. Will Kang Chul-In be able to overcome the 9 other Grand Sovereigns in order to grasp the Continent of Pangaea within his hands?

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

It is the story of a young man who died and was reborn as a level 1 skeleton soldier in an underground world. Follow our protagonist as he struggles to survive in a foreign, RPG-like setting surrounded by danger and monsters. Watch as he levels up and overcomes all obstacles through sheer perseverance and wit, rising to prominence