This new, "system-born" monster serves as a terrifying antagonist that forces the characters to rely on pure grit rather than standard power-ups. The Supporting Cast Steps Up
The second half of the season (Part 2) follows Bell and Ryuu as they are isolated on the 37th floor, injured and nearly out of supplies.
The most striking feature of Season 4 is its shift toward a "dark souls" or survival-horror atmosphere. While previous seasons occasionally touched on danger, Season 4 fully commits to the overwhelming lethality of the dungeon. Reviewers from GameRant and Anime News Network noted that the show finally conveys the true terror of the "Deep Floors," where mistakes often lead to immediate, gruesome death.
Is It Wrong to Try to Pick Up Girls in a Dungeon? IV (Danmachi IV) is widely considered a "peak" for the series, successfully pivoting from a lighthearted fantasy adventure into a gritty, high-stakes survival story. This season, which adapts volumes 12 through 14 of the light novels, is split into two parts: the Labyrinth Arc and the Calamity Arc.
One of the most praised aspects of the season is that Bell’s friends—Welf, Mikoto, Haruhime, and Lili—are given room to shine without him. Is It Wrong to Try to Pick Up Girls in a Dungeon? season 4
Season 4 is arguably Ryuu Lion's season. The narrative focuses heavily on her tragic past with the Astraea Familia and her struggle with "justice".