Rebirth: 100 Days Before Doomsday - Chapter 44: Rune

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?

She, a renowned assassin of the 21st century, actually crossed over to become Su Manor’s most useless good-for-nothing Fourth Miss.

He, Jin Empire’s imperial highness, was an emotionless overbearing demonic tyrant with unrivaled talent.

Everyone knew that she was idiotic and good-for-nothing and bullied her as they pleased. But only he, the overbearing tyrant with the discerning eye, wouldn’t let go of her even if his life depended on it.

For the time being, let’s just see how the stubborn versus stubborn clash and play out in this good show of the chaser and the chased.

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates

Though he received the skills necessary to teleport across worlds, the king who performed the summoning ritual attempted to trick him into wearing a slavery collar, this annoyed him so he kidnapped the princess and returned to Earth.