Inventory of Chaos: Iconic Scenes That Shattered Everyone Instantly - Chapter 14: ICISEI Episode

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.

Born with a seed of immortality, he rose from the Han tribe at the end of the century, and embarked on the road of immortality, step by step, until he reached the other side of immortality.

Efforts will pay off. For cultivators, what better golden finger is there?

- Description from novelbuddy

Reborn as a sword, he lived for hundreds of years, and then he occupied the body of a 15-year-old prince.