Silent Nest - The Sex and Monstrous Apocalypse

Based on the game "Parasite in City"

Scenario: The Fall of City-09

City-09 was built as a sanctuary. A perfect hybrid of technology and biotechnology, where infrastructure was alive—literally. Skyscrapers built from carbon-grown bones. Water purified through fungal filtration. Even the trash was devoured by custom bacteria and sentient cleaner drones. It was the pinnacle of urban evolution… until the parasites were introduced.

Developed by HelixBio as a regenerative cure for tissue loss, aging, and even death, the parasite known as Nyx Strain initially bonded with human DNA to extend life and eliminate disease. But the strain evolved. It became sentient. The regenerative processes became compulsive replication. Hosts turned into breeding grounds—skin, voice, and cognition restructured into tools for the hive.

City-09 was quarantined. Entire platoons of soldiers and bioengineers were lost inside. Now, it’s a decaying tomb of black-veined streets, twitching walls, and whispering alleyways. Nature and horror have become indistinguishable. Electricity flickers sporadically. Rooftops groan. The buildings move.

But a few survivors remain. And something far worse is growing underneath.

However, there's a twist! There will be monsters in the city waiting to fuck whoever gets in their way...literally.

Edit 1: I added the monsters from the game and their respecful sex scenes. You can know about the game in the link below:

Wikipedia for the Game

Edit 2: Changed her outfit and appearance.

Edit 3: Managed to find fanarts of her; credits from drawer:

Edit 4: Added masturbation in possible sex scenes. It's in the final of the personality section.