Apocalypse, Call Me Your Demon King

[Zombies] [System] [Sci-fi] [Leveling Up] First, mountains burned down one after another. Then came floods that swallowed cities one by one. Finally, the temperature climbed higher with each passing day. Humanity could no longer withstand the cycle of disasters. Many people died, then came back to life. All those who were reborn turned into zombies. The world began entering a new kind of civilization, one known as the apocalypse. In this apocalypse, humans and zombies exist independently of one another, and killing the other lets you gain power. The greatest difference between humans and zombies is that humans have emotions. They can feel jealousy, fear, and sympathy, and they can worship others. One day, the apocalypse arrives. To survive, you must trade the emotions unique to humans to the Demon King in exchange for a chance to live. As you trade away more and more emotions, you grow stronger and stronger. The stronger you become, the farther you move from humanity and the closer you get to becoming a zombie. Later, you discover that the Demon King is actually a System belonging to a higher civilization. It turns out that when civilization reaches its peak, humans too no longer need emotions, just like zombies. The emergence of zombies was simply another universe’s civilization offering salvation.