The World Does Not Exist for ■■

This world is not real, and I am not the protagonist.

Review from the RAW site:
The story begins during World War II, when a portal to a medieval fantasy world opens on Earth, altering the course of history. The protagonist lives as a janitor in Incheon, Korea, and one day, after mumbling about status windows and leveling up, his employer murders his family and colleagues, setting the story in motion.

At first glance, it may seem like the typical introduction from an NPC’s point of view in a game, but this universe contemplates what if a medieval fantasy world had connected to Earth during World War II? It unfolds in such an intriguing way. For instance, the defeated Nazis flee to the fantasy world, where Hitler becomes a Demon King, and the deities of the fantasy world, regarded as “spiritual life forms” by Stalin, are demeaned, resulting in the massacre of vampires and dwarves by the Soviet Union. Communism is spread in the Middle Ages, inciting serfs to revolt, and elves, seeking the elixir of life, face nuclear bombings on the World Tree by Americans, leading to the elves turning into communist guerrillas. It’s a world that makes you go, “What is this?” Personally, I found the universe to be immensely charming. The story includes the effects of the Great Depression on the United States, the crumbling economy of a collapsed empire, magic towers shaking from the air conditioning revolution, and the tale of a hero who has left descendants among all races.