Global Demon King: Starting as the Abyssal Dragon - Chapter 15

A man was transported to Ancient China and eventually became a servant of a declining household without a male heir. He utilized his wits and modern knowledge to help the household and eventually become trapped in the sea of political turmoils of the period.

- Description from Novelupdates

Science and Technology Library: The supreme state of science is theology; an accidental rescue, let Chen Mo get a technology library that collects endless technology, the story begins…

- Description from xbiquge translation

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?

Silas Greenfield, a master assassin, dies in a bloody betrayal — only to wake up in the body of a random extra in a fantasy world straight out of a game he used to play. But Silas isn’t here to follow some prewritten plot. With his deadly skills and sharp mind, he’s determined to rewrite the rules and carve his own path.In a kingdom full of power struggles, royal intrigue, and dangerous secrets, Silas must navigate a world where everyone has their role — and he’s ready to break them all.Can a former assassin outwit fate and rise to power, or will he become just another pawn in a game he refuses to play?