Fated Mark [ABO]

Setting: A natural disaster transformed the planet. Miasma blanketed the surface, turning it into a wasteland, while humans discovered vast habitable spaces beneath the swamps.

There was no sunlight and no oxygen, only glowing spores and poisonous life forms. Once living beings awakened, they became immune to the swamp's toxins and survived by breathing in a mysterious light source.

The upper echelon of humanity, whose genes had awakened, used data matching to select their destined partners and preserve civilization.

As commander of the base's finest hunting team, Mu Zhao had always believed his destined contract partner would be a gentle, considerate omega.

But during a mission, an unknown monster bit him. When he woke, he discovered he had turned into an O and had been marked by the cold-faced colonel he hated most!

Under the lights, the doctor read out the figures on the report in a detached voice. "Strength reduced by 50%. Endocrine system disrupted by 99%. Base toxin resistance reduced to 0.1% of its original level..."

"According to our calculations, Commander Mu Zhao's chance of surviving on his own is as low as 0.0001%. He must be marked repeatedly by his destined alpha to survive."

"And the only way to awaken again is to receive a permanent mark."

*

Song Yanting, the base's highest-ranking colonel, was one of the most outstanding alphas: perfect-looking and immensely capable. Apart from being cold-blooded and ruthless, he was every omega's dream man.

Commander Mu Zhao was much the same: an alpha second only to the colonel and highly sought after at the base.

Unfortunately, although both had been of matching age for years, the data had never found a compatible partner for either of them.

Until one day, the commander lost his abilities, transformed into an omega, and became the colonel's destined partner.

"..."

At first, Song Yanting found the commander troublesome and in the way. Whenever he was marked, the commander looked as though he were enduring some great humiliation, as if someone had wronged him.

But after marking him again and again, Song Yanting suddenly began to think that the omega sobbing in his arms was rather cute.

Note: The setting allows for childbirth, but the main characters do not have children.

The recipient only cries during sex; the rest of the time, he's very alpha. The top is genuinely cold-blooded at first, and the two can't stand each other.

Theme: Protecting the environment is everyone's responsibility.