Tondemo Skill de Isekai Hourou Meshi - Chapter 48

The world was destroyed, torn to shreds by the war as it raged on. With the falling of nuclear bombs, the mutation strangely adapted and became an entirely new element.Those who couldn't withstand this mutation became beings tethering on the edge of life and death, becoming undead.Only a small population remains on the earth now.In this small population, some can adapt to the mutation and awaken unique powers in the apocalypse, while others are entirely unaffected, still like normal people.Ray was just a normal E-class awakener, but a faithful purple crystal changed everything.Through the purple crystal, a “system” activated inside him, which could allow him to get stronger the more he spreads his genes.Necromancer, wizard, martial artist to sorcerer - every single skill was possible as long as he spread his genes.From that moment, Ray walked the path of spreading his genes “for the sake of humanity.”#no ntr, yaoi or yuri

A side story series featuring the girls of Kyoukai Senjou no Horizon.

She had a dream: the world was brimming with light. Family. School. Friends. Trains. Buses. Movies. Books. In that world of light, she grew into adulthood… and at the very end, in a white room, she fell into darkness. She awoke from the dream to find that she had become a demon. In the demon world, she lived a carefree life until she encountered a powerful being.

Doomsday comes, and human beings enter the heavenly world.
Ten years later, Yang Chen, who was betrayed tragically, returned strongly with the Tianyu bug. In this life, he vowed to make the betrayal pay the price. He has a powerful bug bonus, just like an open hang. Frightened to hear…

- Description from novelbuddy