"Immorality" is a dark fantasy anime series set in a dystopian world where humanity is plagued by a mysterious phenomenon known as the "Eclipse," which corrupts both people and the environment, turning them into monstrous entities called "Hollows." The story centers on Kael, a former soldier turned rogue mercenary, who possesses a rare immunity to the Eclipse. Kael's immunity makes him a target for various factions vying for control over the Hollows and the secrets behind the Eclipse.

The narrative begins with Kael being hired by a clandestine organization known as the Obsidian Order to retrieve a powerful artifact called the "Eclipsed Shard," believed to hold the key to reversing the corruption. Along the way, Kael encounters Lyra, a skilled but enigmatic thief with her own ties to the Eclipse, and Riven, a disillusioned scientist seeking redemption for his role in the catastrophe. Together, the trio navigates a morally ambiguous world filled with treacherous alliances, betrayals, and the ever-present threat of Hollows.

As the story progresses, Kael and his companions uncover the truth behind the Eclipse: it was not a natural disaster but a man-made experiment gone awry, orchestrated by a shadowy cabal seeking to transcend human limitations. The cabal, known as the Ascendancy, views the Eclipse as a necessary step in human evolution, even at the cost of countless lives. Kael's immunity is revealed to be a result of his exposure to an early prototype of the Eclipse, making him a living weapon against the Ascendancy's plans.

The series delves into themes of morality, survival, and the consequences of unchecked ambition. Kael's journey is marked by internal conflict as he grapples with his own humanity and the weight of his immunity, which isolates him from others. Lyra's past as a former member of the Ascendancy adds layers of complexity to her motivations, while Riven's scientific expertise becomes crucial in understanding and potentially reversing the Eclipse. The narrative builds toward a climactic confrontation with the Ascendancy, where Kael must decide whether to destroy the Eclipsed Shard to end the corruption or use it to gain power and control over the Hollows.

The anime features a richly developed world with intricate lore, blending elements of science fiction and fantasy. The Hollows serve as both a physical threat and a symbolic representation of humanity's darker impulses. The series maintains a tense, atmospheric tone, punctuated by moments of intense action and emotional depth. The characters' relationships evolve organically, driven by their shared struggles and conflicting ideals, making "Immorality" a compelling exploration of survival in a world where the line between right and wrong is increasingly blurred.