MTL - Mystery Hunter - Chapter 14 Doubtful

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?

Gou Liang was originally a small office worker of the Space-Time Administration Bureau but because of a weird questionnaire, he was sent to multiple worlds in order to complete a mysterious and arduous mission — to use the correct posture to awaken lord god.

A world where one’s life was decided by one’s talent called Gift.
The main character Erio Scarlet who was born in the house of influential noble family that had produced a lot of Holy Knights manifested a suspicious gift Incubus in the conferment ceremony. Furthermore the skill attached to that Gift was only one embarrassing skill called Peerless.

Erio was banished from the city because there was no way his indecent existence could be permitted in a family of Holy Knights but……somehow he went through an amazing growth when he dealt with his horniness though!?

In addition when his childhood friend who was bestowed with the Gift Sacred Knight chased after the main character because of her love for him reverse ra-……did it with him, a lot of powerful indecent skills showed up and on top of that they even got bound by Master-Servant contract……!?

This was the indecent heroic tale of the boy who was gifted with indecent Gift rising in the world while [getting along] with a lot of girls.

He is very cold and passionate, Mu Yanwang, who means what he says. He has always regarded women as dirt but she, he has only spoiled her.

At first, he said with overbearing arrogance – “Even you are mine.” Afterwards, he gradually fell for the enemy – “Mine is yours.” Finally, he surrendered obediently, – “Ning Xiaofei, I’m also yours.”

Ning Xiaofei, his little wife. He just wants to put her in the palms of his hand, to love.

- Description from Novelupdates