"Chōjin Densetsu Urotsukidōji: Kyōō-hen Gekijō V2 Kyōya Majū-den" is a continuation of the "Urotsukidōji" series, a dark fantasy anime rooted in supernatural and horror themes. The narrative revolves around the struggle between humans, demons, and otherworldly entities in a chaotic battle for dominance across multiple dimensions. The story is set in a world where the boundaries between the human realm, the demon realm, and the mystical Makai (Demon World) are increasingly blurred, leading to escalating conflict.

The central figure, Amano Jyaku, is a half-human, half-demon entity destined to play a pivotal role in the merging of the three realms. His journey intertwines with the ambitions of powerful demon lords, such as Overfiend and Emperor Cho, who seek to exploit the chaos for their own gain. Amano's transformation into the Overfiend, a being of immense power capable of reshaping reality, becomes a focal point of the narrative. His actions trigger a cascade of events that threaten to destroy the fragile balance between the realms.

Key characters include Nagumo, a human caught in the crossfire of the supernatural war, and Akemi, a woman whose fate becomes entwined with Amano's. The demon lords, including the enigmatic and ruthless Emperor Cho, vie for control over the Overfiend's power, leading to alliances, betrayals, and brutal confrontations. The story delves into themes of power, corruption, and the consequences of unchecked ambition, as characters grapple with their roles in the unfolding apocalypse.

The plot is marked by intense action sequences, graphic depictions of violence, and surreal, otherworldly imagery. The narrative explores the moral ambiguity of its characters, with no clear distinction between heroes and villains. The series builds on the lore of the "Urotsukidōji" universe, expanding on the mythology of the Makai and the prophecies surrounding the Overfiend. The story culminates in a climactic battle that determines the fate of the realms, leaving lasting implications for the characters and the world they inhabit.