After Engine Dai-Shogun crashes on Earth, the Go-on teams head to ground zero as S?suke remembered their adventure in the Samurai World and how the Hon?sh? Warriors died fighting Maki as Engine Dai-Shogun. However, Harunosuke reveals that the sword he and brother were protecting actually holds part of Retsu-Taka's soul that can control Engine Dai-Shogun. By then, the Y?ma Rairaiken and Gokugokumaru arrive to get the sword as Go-on Teams fight them. But a surprise visit by the Human World counterpart of Retsu-Taka results in the revived Engine Dai-Shogun acting on the man's will to attack the city out of rage. As Engine-Oh, GunBir-Oh, and Seiku-Oh attempt to stop the stronger Engine Dai Shogun, the Y?ma backstab the Gaiark Ministers and dump them into the Bikkurium chamber as they reveal their intent to take over the Human World once Engine Dai-Shogun devastates the city. Later, after coming to from the fight, S?suke finds "Retsu-Taka" to reason him into stopping this madness, resulting in a fist fight with the man after revealing his reason being to getting back on society for his misfortune in becoming homeless. Seeing he has no choice but to destroy Engine Dai-Shogun if he has to stop the destruction, Go-on Red attempts to form Kyoretsu-Oh when the Y?ma stop Go-on Red and he fights the two single-handedly before the others join in the fight, forcing the Y?ma to sic Engine Dai-Shogun on them. However, "Retsu-Taka" runs into scene and uses Retsu-Taka's power to break the combination as the Y?ma use the Bikkurium vials they took to enlarge and finish the job. However, the primary Go-ongers place their partner Engine Souls into the Wandering Engine Casts to form Engine Dai-Shogun and destroy the two Y?ma once and for all while "Retsu-Taka" gives the Engine Sword back to Harunosuke. Soon after, the brothers ride in the Ancient Engines with the Wandering Engine Casts to return to the Samurai World while "Retsu-Taka" begins a new life for himself.