Rebirth in the Apocalypse: Third Time's a Charm - Chapter 172

“What’s my class?”[Beast Tamer – Class E]“..Seriously?”Lee Min-Jae was a workaholic with no social life who died slumped over his keyboard. When he opened his eyes, he was in an RPG-like world — but with the worst class imaginable: Tamer.Tamers were seen as useless. Weak. Limited to disloyal, expensive-to-keep wild monsters.But he wasn’t just any fool. He was a systems-obsessed gamer, an expert at finding exploits and shortcuts.With his cold, analytical mind, he chose to break the game’s rules — by leveraging the most reviled mechanic of all: contracts.Where others saw abomination, he saw an exploit. And he was ready to turn the worst class into something unbeatable.---------------This story have:[Adventure][Smut][MSmut] (no NTR).[Harem][System / LitRPG][Strategy] - cold planning, exploiting mechanics, creative use of abilities.[Cold and Calculating Protagonist] – no naive romance.[Worldbuildin] – rules, politics, economy.[No NTR] – the protagonist is not betrayed, no passive humiliation content.

She fought in the Battle of Changping and witnessed the killing of hundreds of thousands. She once led the Qin Iron Calvary and battled against the Six Kingdoms. She has seen a third of the land and witnessed the breaking of mountains and rivers. The sound of a grand zither and the light of a great female emperor. A prosperous world that was forged on the battlefield. Yet, these two thousand years are forgotten from history.

- Description from Novelupdates

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.