While Xio members are on their way to a test site to turn monsters into Spark Dolls, Black King attacks them while Alien Nackle Bandero tries to steal the Spark Dolls. Ultraman X appears but is weakened by both the monster and alien until Ultraman Zero appears to assist Ultraman X. Bandero gets away and takes the Spark Dolls with him, while also unintentionally taking Rui along for the ride. With Rui on Planet Gilmo, Xio invents the Ultimate Zero Card, while Ultraman Zero talks to Ultraman X and insists that he will save Rui. With the card completed, Daichi as Ultraman X uses it to get to Planet Guillermo, where he joins Ultraman Zero in battling Bandero and Black King Drill Custom. After the battle ended, Rui takes a photo with the two Ultramen and Ultraman Zero bids farewell to Ultraman X, who hopes that they will meet again some other time