Dungeon? This Tree? Why Don't You Join Me for Lunch? (Dungeon Core) - Chapter 37: Karma

Having lived a normal life all his life and died without being able to fulfill his desire and when he’s given a task by a god, watch how he takes the protagonists girls while making it hard for the hero.

Innate Spirits are the physical manifestation of people’s souls, proof of their deepest desires and true nature.In a world where the powerful rule everything, those with weak or nonexistent spirits are completely dismissed.When children attain the age of 16, every child awakens their Innate Spirit through the awakening test, a moment that determines their fate all through their life.Cole was immediately termed trash. He failed to awaken, and all that was in the place of his spirit was an obscure figure no one could make out, but its presence briefly seemed to oppress all present.The feeling was fleeting, and Cole was branded as worthless; he was set to be reduced to nothing but a servant, discarded by a world that values power above all else.Desperate to defy his fate, Cole chased a chance at change, only to be met with overwhelming danger.In the face of death, his soul finally responded, and his innate spirit awakened.But the earth-shattering power he expected never came; instead, he received a book.Runes are deeply engraved all over its cover. Giving off intense oppressive vibes.A book that would grow alongside him and one day become the foundation upon which all life and all laws are rewritten.

In the tenth year after the new era, the world finally came to an end. Zhang Mu truefully waited for his death, but unexpectedly found that he had returned to ten years ago. With his memory about the future, he swore that he would change the calamitous history, saving the earth from being destroyed! Walking dead, zergs, evolvers, and various mutated animals… nothing can stop him! The first step is to retrieve his identity as an era merchant , then find all the treasures he can remember to enhance himself!

- Description from Novelupdates

In a future timeline, the earth was visited by a species known as the Slarkovs.
Having lost their home planet and in search of a new one, earth was the next habitable planet for them.

Humans and Slarkovs made a deal with each other in return for the Slarkovs living on earth.
The Slarkovs traded their technology and knowledge for a new home.
They were similar to humans except for some of them who had slight differences so fitting into the society wasn't a problem.
Over the years Slarkovs and humans began to mate with one another and reproduce offsprings.
This in turn created a new species known as the mixed-blood.
Centuries later mixedbloods could tap into their bloodline and perform unimaginable feats.

Gustav born into an age where bloodline determines everything, struggles to fit with a useless bloodline.
His bloodline only grants him the ability to change his hair color, destroying his hopes and dreams for a great future.
His fate is turned around when an unexpected situation leads to him finding a system that grants him the power to unlock and upgrade bloodlines by completing quests but he's baffled by two quests with a five-year deadline. Success will grant him unimaginable rewards...
But only one thing awaits him if he fails... Death!

Follow Gustav on his interesting journey filled with unprecedented adventures, danger and death, maybe?