I Become Master of Danger Zones as Incubus With Mastery In Genetic - Chapter 754 : 174

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

Indra (5) grew up in her family while being shunned and ostracized. When she regained the memories of her previous life, she decided to run away from home and thus trained herself to absurdity.

During her training, she encountered the young adventurer Sword, who looked just like a middle-aged guy. Worrying about the impertinent, eccentric, pointlessly strong young girl, Sword invited her to go on a journey with him.

[You have entered the dungeon at Gwachun Station’s 1st Exit.] When former high school student Kang Woojin finds himself returned back to Earth after being forcibly summoned to a foreign planet for 20 years, he soon finds that Earth is not the same, normal place as he once remembered it to be.