Contract Marriage: Emperor CEO's Secretary Wife - Chapter 219 - Reason for his disappearance

Choi Hyun-seok, a heavyweight champion of the biggest mixed martial arts league on Earth and the one who was called the strongest had died.Afterwards, he was granted new life as a hero in another world.‘Wealth! Honor! Endless beauties at your fingertips!’With thoughts of such a dazzling future, the first thing that he saw when he came to this new world was a towering ox monster.The monster, who was the commander of the demon army, asked.“Hero? You’re saying you’re the hero?”“Uh…I think…?”And so, that was the start of hell.

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?

Power comes with a cost... and it was something she was willing to trade her soul for.A few nights before her wedding, Lauren sought a way to break her fourth engagement. Known for her bad reputation as the rebel princess, she was the only lady who had the guts to step foot on the Everston mansion, the house of a notorious warlord, in the middle of the night.She offered him a wicked alliance that the entire kingdom did not see coming: a marriage.A vixen pretending to be a damsel in distress and a man whose crimson eyes screaming for bloodshed. Could something blossom in this treacherous dance of lies and deception?--“Are you upset?”She eyed him sharply. “Should I be honored that I got tricked by you, milord?”He drank the remaining wine in his glass with one gulp and put it on the wooden table.He stepped in front of her. His hand was on the rail on her side while his other hand grabbed her glass and finished her wine before putting it down.The way his Adam's apple moved with his every violent gulp made her feel a tickling heat around her nape.When he brought his attention back to her, he licked his lips to wipe off the trace of wine.“How shall I make it up to you then?” he asked with his deep voice, like a seductive devil asking his victim how she would like to be killed. Dangerous yet… enthralling.

There was once an immortal cultivator fighting for the fate of human beings. Unfortunately, he failed that time; but fortunately got another chance as he was reborn once more as a human, on the earth of 5,000 years ago. With a second chance, he not only would embark on the road of saving all mankind, but also would retrieve his human nature on the new journey that would last for 5,000 years.

- Description from Novelupdates