Rebirth: Revenge of the abandoned heirress - Chapter 13: First one

Mo Ran felt that taking Chu Wanning as his master was a mistake.

His Shizun was just so similar to a cat, while he was like a silly dog.

Dogs and cats were biologically different. The silly dog hadn’t originally intended to put his furry paws out towards that cat.

He originally thought that dogs should be with dogs, like his senior brother, who was beautiful and docile, like a cute Japanese Spitz. They would look so good together.

But after dying and coming back to life, after living two lifetimes, the one he’d brought back to his den both times was that snow-white kitty Shizun that he didn’t even have his eye on at first.

- 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?

In his old world, Elric had nothing—no powerful family, no elite degree, just relentless hard work and a passion for healing. Dismissed as a third-rate doctor, he shocked the nation by saving a congressman’s life and becoming an overnight celebrity. But just when his career was rising, tragedy struck.Now, Elric opens his eyes in a world unlike any he’s ever known—a land of swords, sorcery, and strange beliefs. Reborn in the countryside of a magical kingdom, where even a common cold is blamed on spirits, he’s the only one who understands how the human body truly works.With no palace, no power, and no one to trust, Elric sets up a humble clinic in a rural village. Armed with science and sarcasm, he treats the sick, challenges ancient traditions, and slowly earns the awe and fear of a world ruled by magic.Mocked as a fraud. Hunted by rival healers. Feared by nobles and mages alike.But this world is about to learn—Even a third-rate doctor can change history.

Ryu Han-bin, the main character who fell into a new world after being chosen as a ‘suitable person’.

Because of the error in the guidelines, the training is repeated endlessly…