A Wild Last Boss Appeared - Chapter 120

In a world where martial artists reign supreme, strength is everything. Unfortunately, that logic doesn't apply to a certain Florida Man.

Refined in the nuclear fallout wasteland, Leo was the strongest mutant alive. He carried an alien artifact, allowing him to exchange his lifespan for modern items. After 50,000 years of solitary life in a humanless world, he collected enough lifespan to transmigrate to another habitable world.

Leo was later thrown into a mysterious planet. He soon discovered that his body produced radiation, and it mutated the surrounding plants and grasses. Worrying that he might ruin the beautiful planet, he chose to live in seclusion.

Unfortunately, the local population soon discovered his existence, and a misunderstanding ensued.

Before her rebirth, Wei Luo was an innocent little girl.

When Caesar learned that he had traveled to the world of pirates!

In order to become stronger, I started hell-style training, looking forward to going to sea one day,

Stir up the situation and rule the world!

One day, a pirate group came.

Looking at the familiar figures behind the captain,

Caesar instantly knew his name – Lockes!

After the Island of the Gods incident…

Garp: When did a Caesar appear in the Rocks Pirates? Almost fell into his hands!

Roger: What kind of strange ability is this? Domineering! ?

White Beard: The scars on my body are thanks to Caesar!

Golden Lion: How is it possible! What ability is he hiding! ?

Kaido: Bastard, it turns out that this guy has been paddling all the time!

- Description from novelbuddy

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.