Esper Harem in the Apocalypse - Chapter 12 - The Super Gene Experiment

800 years ago, 3000 dimensional gates opened across the entire world. In that moment, it was as if 3000 different colored eyes opened across the world as hordes of monsters swarmed out of these gates like tears.

Some could destroy city walls with one strike; They had bodies the size of a giant and fed on humans

Some latched onto humans, absorbing their bodies’ nutrients and enslaving humans

Some infiltrated the humans’ cities, disguising themselves as normal human beings while feeding upon human blood to sustain themselves.

In a night, the Human race fell to the bottom of the food chain.

The world had turned into a paradise for monsters…

- Description from Novelupdates

The maniac who was crazy about all kinds of fields such as military and steampunk had been reincarnated.

However, his father was King Sejong the Great?

The mania-wise king and his crazy maniac son.

Along with the ministers, and countless humans who were getting exploited.

Even today, the night of Joseon was filled with the light of overtime.

Nine Tribulation Immortal Emperor, reborn in the city!One Earth, one Immortal Realm, the difference is as vast as that between heaven and earth!

“Hmph, my dumb big sister is in danger!” A mischievous grin spread across his face. “Hehehehe... this gives me the perfect excuse to finally use this treasure I’ve acquired but never bothered with!” He rummaged through his belongings, carefully selecting various items. “A bit of this... and this... and a dash of this.” Boom! The explosion of energy sent a ripple through the air as he laughed maniacally. “Hahaha! It’s done! Now, all I need is a compatible host for it.” Years later... “Did I overdo it?” he wondered in awe, watching as his creation wreaked havoc, conquering world after world with ease, as though stealing candies from children.