Dragoon - Dragoon 77: The Oath and the Little Brother

SSR-ranked killer Mu Hui died in an explosion, only waking up to find herself transmigrated into the body of a vicious female supporting character in a book.

For the wine to be drunk on her wedding night to actually have been a cup of poison and for the one to poison her to be her husband, who would believe it?

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?

“When I left you, it wasn’t because I was materialistic.”

“I know.”

“He doesn’t love me. I already broke up with him.”

“I know.”

“You knew? I didn’t know you were still so concerned about me…”

“I know because he and I are now a couple.”

This is a story about how a poor loser turned into a tall, handsome and rich guy and snatched his ex-girlfriend’s current boyfriend away.

- Description from Novelupdates