The Absolutely Unbeatable Dungeon

After a fatal accident, Hitoya is reborn from modern-day Japan into a game-like world as a monster dwelling in a dungeon. In this world, monsters are endlessly hunted by humans and exploited as mere materials a relentlessly unfair existence. His desire to protect his fellow monsters drives him to awaken. Becoming a dungeon boss far beyond the norm, he sets his sights on creating an SSSrank dungeon that absolutely no one can ever conquer.x If you want, I can also tighten the title for a webtoon thumbnail, like "Unclearable: SSS-Rank Dungeon Boss".