Doomsday Online: Supreme Blessing - Chapter 8: Demon Sealing Arrow Luo Xingyao

The day she transmigrated it, she was already the wife of two men. She later became the Queen of the country. Her life has been cherished by seven men.

- 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?

Nidel, who belonged to the Technological Magic Order that held low prestige, became the bodyguard of a foreign prince behind the scenes. Left with no choice, he assumed the role of a bodyguard, turning into a black cat using the transformation magic he prided himself in, but the one who assumed the role as official bodyguard was the Royal Knight Legato. Nidel, who one-sidedly held feelings of affection towards Legato, thought of this circumstance to be interesting, butー