Shinigami in the Ninja World - Chapter 13: Missing Half

Skyscraper's rooftop.Fang Cheng is sweating heavily, relentlessly training.1000 airborne clapping push-ups.1000 two-finger push-ups.1000 one-arm pull-ups.1000 one-arm handstand push-ups.1000 single-leg squats.Plus, holding a dragon flag and a Baki plank for one hour.Looking in the mirror, Fang Cheng shows a satisfied expression.“All six skills are maxed out, I can finally synthesize the mythic talent, Asura's body.”Neon-lit chaotic dark city, countless crimson eyes lurking around.Conglomerates, serial killers, cultists, gene-modified beings, rebel groups…Fang Cheng, with his panel, intrudes into this seemingly ordinary mysterious world.Gaining experience and cultivating through push-ups.Fitness, boxing, sanda, parkour, meditation, breathing, qigong…Each seemingly ordinary skill achieves unimaginable heights.Pushing human limits ever higher, crushing every so-called “monster.”Until — becoming the god of the new world!

This novel is also known as From The Start, I Traded A Galactic Warship

After getting a trading platform three thousand years later, everything in the world has become an antique, worth a thousand gold.

But it was also learned that three years later, aliens invaded, human beings fell, and the dark starry era began.

In this era of unprecedented change in tens of thousands of years.

Shen Shi decided.

First trade a space battleship, and then talk about it.

then–

Battleships come to the world from outer space! Global shock! Starry Sky Era, open in advance!

- Description from novelbuddy

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?

While the demons were rising, mankind was about to become extinct. Six temples rose and protected the last territory of mankind.

A young boy joins the temple as a knight to save his mother. During his journey full of miracles and tricks in the world where temples and demons are antagonistic to each other, will he be able to ascend to the strongest knight and inherit the sealed divine throne?

- Description from novelupdates