Valkyrie Smash - Chapter 5 Well Yes, But Actually No.

The apocalypse arrived, and Irving was betrayed and killed by his own girlfriend.After his rebirth, he was chosen by the Will of the Blue Star to be an internal beta tester of the Shelter Game, starting with a [Tenfold Drop Rate] and becoming a [Necromancer]!Ferocious and brutal exotic beasts are all tamed by him, gradually forming a powerful “Exotic Beast Legion” under his command!Building sanctuaries, hoarding supplies, upgrading outer walls, setting traps...Constructing the most powerful fortress in the apocalypse!“Since I have been given a second life, I will trample those who've betrayed me once under my feet!”...When the Dark Lord descended, Irving's shelter had become the strongest on the Blue Star!“You evil creatures, dare to covet Blue Star?”“Come on! Let me show you what true despair is...”“Remember, from now on, Blue Star is under my protection! Got it?”

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.

Genius, antisocial, solitary, intractable , maniacal.

At the turn of every era, it is he who raises the flag of the rebel cross.

Winners take it all, losers take the fall.

He who brings order to a chaotic world, assembles talents and masterminds.

He who hides among the crowd, yet stands on the top of the world.

— The one and only, him.

- Description from Novelupdates

Great Cultivator Chen Fan had failed his Tribulation period, but after a dream, he had returned to Earth, when he was young, five hundred years ago.