Alpha Razor King - Chapter 31: You Can’t Leave.

A human warrior cultivating the Ancient Strengthening Technique has transcended dimensions and arrived on Kyushu. Together with twelve ravishing beauties with looks that were unmatched in their generation, will he be able to stand on the summit of this world?

Zack “Kazz” Foreman once was a human from the earth when humans went through a dramatic change because of an event. This forced them to evolve into energy-based beings but was sucked into another dimension.

Forced to start living out lives on random worlds in a fractured dimension, Humanity is placed on the path of complete extinction.

This is controlled by a demon king at a place called The Center of Everything.

The Demons try to force Humanity's mark from every reality, so there are only demons, but the Demon King feeds from anger and pain. A constant tournament going at the center of everything to feed his hunger.

Kazz made it to that point once, but was tricked, refused entry to the tournament because he had offed a place one of the gods of the worlds.

Refusing to give up, Kazz goes back to the beginning to start again. To do this, Kazz must give up all of his memories to choke the flow of demons born fully grown from a pool of recycled souls.

This journey starts after he lives a solitary life trying to get stronger but not knowing why. The world Kazz is on is like our earth, but it was only a mimic of the earth we know.

Caught using steroids and about to give up and join the army, Kazz stumbles onto a cave in the ground. He is transported to a world filled with demons and monsters, and a human god named Hero is speaking in his head.

Hero, a person Kazz knew but was not friends with, followed him to help but was lost from him. Upon meeting Kazz, Hero offers him the Hero System to help him advance in this new world.

Kazz refuses after trying to get to the top and failing to use the easy route. This starts a series of frustrating events for both Heroes, but they learn to work as a team over time.

Kazz will meet misbegotten monster girls and demons that he agrees to take care of in this world, using the Ranching System. It only gives bonuses to the girls and skills to help raise them, but he will also learn to control the Elements with Shamanic abilities.

The story starts on earth, after some unknown circumstances, the world was suddenly invaded by monsters from other worlds. Many died and even more turned into zombies, starting what many would call 'The apocalypse Era'.

Rin, a normal teenage boy who lost all of his family members was on the verge of falling into despair when a goddess appeared and sent him to another world that was very similar to a game Rin played before the apocalypse.

Her goal from this was simple, trample on all the protagonists and become the strongest creature in that world for a chance to get back what he thought he lost forever.

Accompanied by a cold beauty, both of them embark on a new journey to become stronger, get back to their world and fix everything.

Gou Liang travels through worlds in order to complete a mysterious and arduous mission…

16 worlds in total:

School Campus: Strawberry Flavored Scholar Gong √
Entertainment circle: Lemon Flavored Film Emperor Gong √
Ancient Time: Honey Tangerine Flavored Shadow Guard Gong √
WuXia: Melon Flavored Senior Brother √
Beastmen: Pineapple flavored Beastmen Gong √
Ghost Spirits: Snow Pear Flavored Dead Gong √
Ancient Time: Gr*pe Flavored Regent Gong √
Apocalypse: Banana Flavored Boss Gong √
Interstellar: Pomegranate Flavored Sentinel Gong √
Modern: Citrus Flavored Aristocrat Gong √
Mecha: Sweet Jujube flavored Lunar New Year Gong √
Ancient Time: Durian Flavored Battle God Gong √
Magic: Watermelon Flavored Blacken Gong √
Cultivation: Cherry Flavored Disciple Gong √
Fantasy: Blueberry Flavored Demon King Gong √
Celestial World: Bayberry flavored Senior Immortal Gong √

- Description from Novelupdates