Go Nagai draws this beautifully. When Akira fights as himself, his movements are deliberate, almost pained. When Amon surfaces, the art becomes jagged, the shadows deepen, and Akira’s face twists into a rictus of pure hatred. For fans who want the deep dive, the 2000 OVA Amon: The Apocalypse of Devilman (often subtitled The Dark Side of Devilman ) is the definitive text. This 45-minute short film discards the human drama and psychological horror of the original in favor of a brutalist, Lynchian nightmare.

But here is the crucial question that the manga constantly asks: Does the engine ever leak into the driver? Throughout the series, we see Akira losing control. When he fights Jinmen (the "Face" demon) or when he battles the militaristic General Zann, we see Akira’s eyes go cold. The cross-shaped scar on his forehead glows. His voice drops an octave.

But visually and thematically, Amon is pure Go Nagai chaos. While other demons have animalistic features—flies, bats, snakes—Amon is humanoid. He is idealized muscle. He is a dark mirror of the heroic physique. His silhouette—bat wings, horned head, clawed hands—is the universal shorthand for "The Devil."