Years after his last battle, Ryu Hayabusa has sought peace, training new disciples at the Hayabusa Village. However, darkness never rests. A mysterious organization known as the Crimson Hand has begun excavating ancient sites across the world, seeking fragments of the Demon Seal—an artifact capable of opening a gateway to the underworld. When the village is attacked and sacred scrolls are stolen, Ryu discovers that the Crimson Hand's leader is Kenzo, a former Dragon Ninja who was presumed dead decades ago. Consumed by dark magic and bent on revenge against the Hayabusa clan, Kenzo plans to unleash the sealed Archfiend Vazdah upon the world. Ryu must track down the scattered fragments before the Crimson Hand can complete the ritual. His journey takes him from the neon-lit streets of Tokyo to forgotten temples in Southeast Asia, frozen monasteries in the Himalayas, and finally to the dimensional rift between worlds. Along the way, he encounters both old allies and new enemies, each with their own stakes in the coming apocalypse. As the blood moon rises, Ryu must confront not only Kenzo and the awakening Archfiend but also the darkness within himself—the same power that could either save the world or doom it.