"Amon - Apocalypse of Devilman" is a two-episode OVA that serves as a reinterpretation and continuation of Go Nagai's classic "Devilman" series. The story is set in a world where demons, ancient and malevolent beings, have begun to re-emerge, threatening humanity's existence. The protagonist, Akira Fudo, is a high school student who becomes the host for the powerful demon Amon, merging with him to become Devilman. This transformation grants Akira immense strength and demonic abilities, but he retains his human heart and conscience, striving to protect humanity from the demonic threat.

The narrative explores the escalating conflict between humans and demons, with Akira at the center of the struggle. As Devilman, he battles various demons, uncovering their plans to overthrow humanity and reclaim the Earth. The story delves into themes of identity, morality, and the duality of human and demonic nature, as Akira grapples with the darker aspects of his newfound powers while maintaining his humanity. His close friend, Miki Makimura, and her family provide emotional grounding, representing the human connections Akira fights to preserve.

The plot intensifies as the demons' influence spreads, leading to widespread chaos and destruction. Akira's battles become increasingly desperate, culminating in a confrontation with the demon lord Zennon, who seeks to plunge the world into darkness. The OVA portrays a bleak and apocalyptic vision, with humanity's survival hanging in the balance. The characters face moral dilemmas and tragic consequences, highlighting the cost of the ongoing war between humans and demons.

The OVA retains the dark, visceral tone of the original "Devilman" series, emphasizing graphic violence and psychological tension. It serves as a condensed yet impactful exploration of the source material's core themes, offering a grim and thought-provoking narrative. The characters, particularly Akira and Miki, are central to the emotional weight of the story, with their relationships and struggles driving the plot forward. "Amon - Apocalypse of Devilman" stands as a compelling addition to the "Devilman" franchise, capturing the essence of its apocalyptic and philosophical undertones.