MTL - Conan’s World Stand-in - Chapter 4 My stand-in is Xiao Hei?

A master assassin transmigrates into an interstellar era.

He crossed over to a new world where humans have magical power. They are called warriors. They use their power to kill the monsters that appear out of nowhere. Dragons, Dungeons, and Magic users are pretty common in this world. If you want to live in peace, you need to have that power. You can also become a powerful clearing dungeon.

In this dangerous world, he has a system that can help him grow stronger. But he didn't want to be a high-profile warrior who attracts much powerhouse attention or become a lab rat. He wants to be Low-profile and grow strong using his system.

The story follows the protagonist, who wakes up one day to find himself in the body of Licht, a villain from a novel he was reading. Licht is a notorious villain who is known for his cruelty and ambition. However, the protagonist soon discovers that he has a natural talent for villainy. He quickly rises through the ranks of the evil organization and becomes a powerful force in the kingdom.

Violet skies, a world undergoing massive changes, a deficient moon, interlinking voids…
When the world experienced a cataclysmic event,the majority of living things ceased to exist. Although humanity survived by hiding in the last safe zones, humans had to face mutated dire beasts and colossal source beasts that could break through the space barrier and enter the earth at any second.
Luo Yunyang, a young man who grew up in those calamitous times, obtained an attribute regulator and set out to walk the path of supremacy!

- Description from novelupdates