Honestly, I think people get thrown by the 'Dungeon Diver' title because it sounds so generic—like a thousand other webcomics. But if we're talking about the manhwa that usually pops up with that search, it's 'Solo Leveling'. The core plot follows this guy, Sung Jin-woo, who's the weakest hunter in a world where gates to monster-filled dungeons appear. After a near-death experience in a particularly nasty dungeon, he gets a unique power: a game-like interface only he can see. He's the only player in this 'system', and the story is basically about his grind from the absolute bottom to the top, unlocking insane skills and reshaping the entire power structure of his world. It's a power fantasy, but the art is what sells it—the monster designs and fight scenes are unreal.
That said, the plot gets way bigger than just leveling up. Around the midway point, it introduces this whole lore about Monarchs and Rulers, ancient beings fighting a proxy war through humanity. Jin-woo's power isn't just a lucky break; it's part of a much larger, darker scheme. The ending is pretty divisive; some folks felt it rushed to tie everything up with a time-loop reset, while others loved the emotional payoff. For me, the main draw was always the visceral satisfaction of watching him utterly dominate opponents who once looked down on him.