Which Dark Isekai Books Feature Antihero Protagonists And Moral Ambiguity?

There's this weirdly specific niche I keep stumbling into lately: dark isekai where the main character is just... kind of a bastard, and I'm into it. It's not about villain protagonists, exactly—those guys are full-on evil from the start. I'm talking about anti-heroes, people who get dumped into a fantasy world and their moral compass gets cracked immediately. They'll do awful things for a goal that might be vaguely sympathetic, or maybe they start decent and the world just grinds them down until they're ruthless. That grey area is where the best stories live for me. The genre mashup is perfect for it, too. A standard portal fantasy sets up expectations of heroism, so watching someone subvert that by making pragmatic, brutal choices hits harder. My absolute favorite example, which I think gets slept on in some circles, is 'The Dungeon of Black Company'. It's a manga/LN, but it fits. The guy gets transported to a fantasy world and immediately uses his modern-world knowledge of corporate exploitation to become the worst kind of capitalist overlord. He's not fighting the demon king; he's fighting unions and maximizing profit off the backs of fantasy creatures. It's hilariously cynical and dark in a very mundane, relatable way. You're not meant to cheer for his cruelty, but you understand the twisted logic. Another one that twisted my expectations was 'Overlord'. Sure, Ainz is overpowered, but the real darkness comes from his gradual emotional detachment. He's not a hero protecting the weak; he's a sovereign protecting his assets, and the 'assets' happen to be sentient beings who adore him. The dissonance there is fantastic. What I find interesting is how these stories often use the anti-hero to critique the isekai genre itself. They ask, what if someone didn't want to be a hero? What if the real fantasy was climbing to the top by any means necessary? The darkness isn't just gore and violence; it's in the moral compromise. You end up reading for the cleverness of their schemes, even as you wince at the collateral damage. That tension keeps the pages turning.