Natural Disaster Apocalypse: From the Start, I Own an Underground Nuclear Power Plant

In the Apocalypse, You Should Build a Private Shelter! Ideally, Bring the Female Lead Along to Lay Low.

Most people don't have such lofty ambitions. Don't have them build some incredibly powerful survivor settlement at the drop of a hat; it's hard to manage and easy to make the story fall apart.

Umbrella Corporation-Type Stories

A huge company with its own underground base and mercenaries, run by a puppet master who controls other countries from behind the scenes.

Looking for Space Satellites, Titan Warships, and Interstellar Warfare

Interstellar warfare

Creating an Alien Civilization and Bringing It to Earth, Any Genre

The protagonist creates an alien civilization or leads one to Earth, where it uses advanced technology to crush humanity.

Any Apocalypse Novels About Building a Shelter and Surviving Alone?

Male protagonist, no harem, and comes with a construction System.

Any Sci-Fi Apocalypse Novels Where the Protagonist Has Their Own Army?

The protagonist has their own army. It could be a fantasy setting with guns, but ideally it would be an army in the apocalypse!

The One About a Six-Year-Old with a System Who Gets a Mecha After 60 Days of Sign-In