MTL - Exile - ~ Chapter 34

What was originally an ordinary day, suddenly became a historical turning point. Enormous, mysterious Cubes appeared all over the world without warning and as if Judgement Day’s spears, inserted themselves into the blue planet.

From inside the enormous Cubes, endless streams of monsters gushed out alike raging tides, utterly defeating the unguarded armies of each state in the blink of an eye.

In order for humanity to preserve its final embers, the heads of states issued orders of retreat, to no longer attack the Cubes but rather to cling to remote cities, which they turned into self-sufficient survivor bases and around which they built 100-meter-tall Walls of Life!

Many years later, while bearing the heavy weight of history, the first expeditionary force brought back a world changing piece of information. The Cubes possessed exceedingly high intelligence and they regularly transmitted mission instructions to humans nearby. The mission rewards were incredible.

Since then, humans rushed out of the confines of the walls and once more set foot on the wasteland!

- Description from Novelupdates

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!

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.