An epic journey into the dark heart of Go Nagai's masterpiece, Devilman, a work that redefined the boundaries of manga and anime, becoming an immortal icon of Japanese pop culture. This book celebrates the genesis and evolution of the Demon Saga, exploring for the first time in depth not only the legendary Devilman, but also its many offshoots: sequels, antecedents, and parallel works created by Nagai's visionary genius. From the first act, which shocked the world with its blend of horror, action, and philosophical reflection, stories unfold that, although they have reached Italy, remain a hidden treasure, appreciated only by the most devoted fans. These works, of the highest quality, stand out for their brilliant insights and memorable endings, but they clash with Nagai's instinctive approach, which he writes and draws "on sight," without a rigorous plan. "Devilman – The Demonic Saga" explores this complexity for the first time, celebrating Nagai's narrative and visual triumphs while also addressing his contradictions, offering a unique insight into the legacy of an author who transformed limitations into art. A must-read for fans and anyone who wants to discover the myth of the Devilman and his tormented universe.