The Abused Luna's Comeback - Chapter 223 - 223 Secrets of History

Cao Xin, a young man on earth, died in a car accident, traveled to a troubled world where supplies were scarce, and obtained a “Bronze Immortal Gate”…

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- Description from novelbuddy

The Grand Sovereign, Kang Chul-In. The man who was so strong that he had to be defeated. Having lost, he must now go back in time to take up the challenge of becoming supreme in the Continent of Pangaea. Will Kang Chul-In be able to overcome the 9 other Grand Sovereigns in order to grasp the Continent of Pangaea within his hands?

Lambert, one of the great generals from Regios kingdom was suspected for planning a rebellion against his lord at the end of unification war, he died an unnatural death. Two hundreds years later, when the era has changed and Regios kingdom entered it’s peaceful era, he accidentally revived as a demon called Undead Knight.. Lambert whose entire body was wrapped in a flashy Demon Metal[Organ] set out on a journey to punish the wrongdoers while enjoying the peaceful sight of Regios kingdom. But…….. This peaceful era was basically an easy mode for Lambert, the greatest general of the chaotic era.

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.