Numbers x Casket - Chapter 13: Monarch’s Relic

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.

When she was rejected by her fiance, everyone laughed at her. Little did they know, she actually loved her fiance's uncle, a trillionaire tycoon, for a long time.Later, she had four doting brothers, numerous secret identities, and a husband who was madly doting on her.Fu Shiyan smirked, pulling her into his embrace, “Dear, when shall we have our third baby?”

Sixty years after the global catastrophe, the Little Freeze Period ended, and the governments of the living regions began to collect land in the anarchic areas to be planned on a large scale, reorganized resources, and entered the recovery stage in an all-round way. These two decades are also called “golden Twenty years”.

This is a bright era in which new regions are rising one after another, politics is set up, capital is acting, careerists are everywhere, heroes are powerful, villains and grassroots are rising together! A young man rises up in troubled times with a full stomach of strategy, hides a tiger in his chest, and measures the world.

- Description from novelbuddy

Jiang Xunyi had transmigrated into a book many years ago, and always tirelessly maintained the requisite accomplishments for a villain.

After finally completing the ultra-difficult task to allow the male protagonist to kill him, an OOC warning had appeared out of the blue——

Error in the actor’s lines, the character role has collapsed, the assigned task has not yet been completed, opening the Rebirth System!

So, he gloriously became… a second idiot son about to be sent to his death.

Lazily idling away the days after changing his identity, he noticed a world-changing difference.

His best friend, the male protagonist, Yun Xie was actually secretly in love with him? Are you kidding me?!

- Description from Novelupdates