Bleach: Watch Closely, This Is How You Use a Zanpakutō - Chapter 210: World

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

Six years ago, the legitimate daughter of the Chu Family was schemed against by her half-sister and was forced to marry the Princely Heir, who was blind and not long for this world.Fortunately, her medical skills were excellent, and she detoxified the Princely Heir.Who would have thought after he came back to life, the emperor would actually want to bestow a concubine upon him—and this jerk didn't even refuse.Furious, she left a divorce letter and then set the Prince Residence on fire, fleeing in haste.Six years later, the same Princely Heir remained a lonely man, with all his old servants worrying their hearts out.One day, upon encountering a Little Baozi on the street who looked strikingly like the Princely Heir, they instantly burst into tears.“The Prince Residence has a successor! Princely Heir, please come back with us to the Prince Residence quickly.”Who knew, Little Baozi disdainfully said, “Not interested.”“Princely Heir, the Prince Residence is immensely wealthy...”“My mother is the wealthiest person!”“Princely Heir, the Prince Residence is extremely safe...”“My mother is the Martial Arts Alliance Hierarch!”“Princely Heir, the Prince Residence has powerful armies...”“My mother is the heir to the Nanduan Kingdom!”Suddenly, a faint voice came from behind: “Then, does your mother need an Imperial Consort? I think myself quite suitable.”

Kaidan (Kaidan refers to eerie tales of strange, mysterious, rare, or bewitching ghosts and monsters from Japanese folklore.) feed on cognition, wield information as weapons, and use information as currency, existing between the peculiarities of neither life nor death.They exist in human rumors and dwell in the shadows of the world.“Does this mean I will become a Kaidan?”In ancient times, they were worshipped as deities, empowered by faith.“Then I am a deity!”In more recent ancient times, they were regarded as demons and fed on fear.“I will become the master of Kaidan!”However, as the tides of time washed over, they gradually vanished, leaving behind only texts considered to be delusions.“To restore the glory of Kaidan is an undeniable duty of ours.”But you are not yet a Kaidan, hmm, nor a person.“Well, becoming a Kaidan counts as success.”

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?