Chronicles of Immortals and Demons in the Apocalypse

I just started writing and didn't think much about a synopsis. I'll fill this in later if I come up with something. Basically, it's about cultivating immortality in the apocalypse with a System. Of course, everyone has this System, not just the protagonist. It's not an invincible power fantasy, and there are no set formulas. I'll write whatever comes to mind and let the plot go wherever it wants. There might be a female lead, who knows?

This novel and its characters are entirely fictional. Any resemblance to actual people or events is purely coincidental. Do not imitate.