Isekai Maou to Shoukan Shoujo no Dorei Majutsu - Volume 12 Chapter 5 part6

Inside the 3000m underwater station, an international group of scientists and engineers live and research for possible settlement of entire human race. Park Mu-hyun, a reserved dentist joins the station in hopes for a quaint life in the deep sea. However, things quickly go south when the station gets attacked by a mysterious group of people.As the water starts to fill in the living quarters, Park Mu-hyun grabs his backpack and immediately runs for his life, but where to? Now, the peaceful station becomes the ultimate survival stage of cult madness and chaos.

When the goddamn story leaves you no choice but to walk the path of the villain,The heroes aren't enough to save the world, as the calamity ultimately kills everyone and everything.Then, only by becoming the demon king can you survive, and only the demon king can save the world, but how?Of course, by conquering every other race, obviously.Can Axel become the demon king and survive, maybe save the world in the process?

Living a dual life, Lucas was a meek boy in school and a Wire Knight on the Internet at night. Surprisingly, he's asked out on a date by one of the most beautiful girls in school.

However, the date ends after a bizarre sequence of unfortunate events, he gets isekaid into another world.

Lucas received a rebellious system and some strange pills as rewards which released the dormant evil within him. He has to control the rooting darkness coming from the previous protagonist of that place and learn how to control his power.

The system promises to fulfil one wish if he will win the game he was sent to. This motivates him to help his sister to get better and become healthy again, he must obey the system and win the game to be granted that wish no matter what.

To form a team with another human, an elf and a so-called 'sex machine'. Lucas has to collect all the avatars and learn how to control them, wield the weapons that were given to him and win the tournament of the place by killing the black wizard.

Time is quickly ticking and there's a huge mess for him to reverse. Starting from his date who suddenly was transformed into a dragon!

Calamity descends upon a a tranquil world in the black of night, transforming it into a death game! This a a true apocalypse, but this is not the end of humanity!

- Description from Novelupdates