The Retired Hero is an Extra - Chapter 209 - : Unexpected Change

For decades, the brave warriors of the Northern Army fought to keep the world safe from the evil Silent Night. But when the fourth-generation leader, Jin Kwan-Ho is accused of colluding with the enemy, he is forced to disband the sect and commit suicide to protect his son, Jin Mu-Won. With no family and allies left, Mu-Won leads a dreary life under close surveillance… until a surprise attack from the Silent Night gives him a chance to escape to the mountains.

There, the young warrior trains to master the fighting techniques of his predecessors, before the mysterious disappearance of a loved one brings him back to the mainland. Follow Jin Mu-Won as he embarks on a journey to avenge his father’s death and take down the villains who threaten to plunge the world into darkness!

Dear comrades, masters, priests, masters, fairies, demons, and leaders, welcome to my world and enjoy the supreme pleasure and supreme enjoyment brought by traveling through various worlds (funny laugh).

- Description from novelbuddy

When she woke up, Lake returned to the classroom of the third year. The classmates were in class with swords and sticks, and the teacher became a female Taoist.
The little fat man in the back seat, how to put two big hammers under his chair.
Rick found this to be a global era!

- Description from Uukanshu (translated)

In a monstrous post-apocalyptic setting, this is a story of how a lowly Inventor, Lance, conquered a nation governed by immoral group of Scientists called The Corporation. He grew and climbed up to the highest rank possible as a Scientist with his inventions and side businesses. Eventually, he became a weapons inventor, building weapons to two opposing sides. In doing so, Lance always crossed a dilemma. How could a nobody topple the most powerful government? How could one overcome circumstances beyond his grasp, especially in a world filled with monstrous mutations called the Abominants?