Kamen Rider: Battride War Genesis

Shadow Moon, eternal rival of Kamen Rider Black, has devised a plan to unmake the legacy of every Kamen Rider who ever lived: kill each hero's first monster before the rider can become one. One by one, the Kamen Riders' histories are erased. Two remain untouched—Kamen Rider Ghost, because he is already dead, and Kamen Rider Den-O, because his Den-Liner can move through time itself. Working across the timeline, Ghost and Den-O must restore the original history before Shadow Moon erases it permanently.