Apocalypse: I Have A Multiplier System - Chapter 23 - : Activation Gem

After an unexpected death, a soul finds itself reincarnated into the body of Itsuka Shido, an ordinary teenager in a world filled with powerful spirits, magic, and dangers from other dimensions. With the help of a mysterious system integrated into his body, Shido gains the ability to travel across worlds, summon legendary anime characters, and unlock a wide array of random skills and abilities.Disclaimer: The cover isn't mine, credits to the original artist.

Have you ever thought about how your life would turn out at the age of 18?Well before I could even say that I was an adult to even say I was going to conquer it.The world had seemed to already be determined of what mine and the rest of humanity would be when the first Leviathans was made public to our world.

[Across the Stunning Beast Princess: Phoenix Against the World]

She, First Princess residence’s only legal daughter, yet known as a waste throughout the whole country!

When her cold eyes opened, she is the 21st Century’s most dangerous genius assassin!

When the sickly young miss exposes an edge, she is absolutely brilliant, and countless men and women in the world greatly admire her……

He is the absolute king of the night, cold blooded and ruthless. In troubled times, he by chance meets her, a zither and flute ensemble, since then in heaven and earth, life and death go hand in hand.

- Description from Novelupdates

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?