Engine Sentai Go-Onger vs. Gekiranger

During the initial battle in the city, Nunchaku Banki uses his powers to transport the Gekirangers into another dimension. This happens as part of Banki's test of his power against Geki Red, Geki Yellow, and Geki Blue. The dimension shift removes the Gekirangers from the immediate battlefield, allowing the Go-ongers to arrive and encounter the Barbaric Machine Beast before it escapes with its quarry.

The Dōkokugan is a sealed artifact that contains the entity Long, a powerful being imprisoned within it. The Gaiark, specifically through Nunchaku Banki and later Meka, pursue the Dōkokugan to extract Long and use his power. Nunchaku Banki demands the sealed Long from Jyan, revealing that the Gaiark's ultimate goal is to weaponize Long's contained energy for their plans.

Master Xia Fu realizes the Gaiark are after the Dōkokugan after being taken to the site.

Meka is revealed as the last fighter from Rinjū Hall, a group of martial artists. The Pollution Ministers bring Meka into the conflict after Nunchaku Banki steals the Engine Souls. Meka uses the stolen Engine Souls as hostages to force Jyan to surrender the Dōkokugan, demonstrating both his cunning and his dedication to completing the Gaiark's mission.

At SCRTC while meeting Master Xia Fu, Hant reveals he once met Miu Suto (referred to as Miki in some translations) at the Kyoryuya Curry Shop. This connection ties the Go-on Wings' history directly to Miki, establishing an unexpected link between the Go-ongers and the Gekirangers' world. It adds a personal dimension to the teams' collaboration and explains why Miu has an interest in the Go-on team.

Long breaks from his seal because he seeks total freedom and wants revenge against those who imprisoned him. He discards his robotic vessel, which was keeping him bound, in order to become completely liberated and pursue his vendetta. This occurs after the Go-on Wings arrive with the resurrected Rio and Mere, shifting the tide of battle.

Long's sealed state within the Dōkokugan has been established from the beginning as the Gaiark's target.

The Go-on Wings arrive to remove the troublemakers from the city and join the battle, using moves learned from Gorie. Go-on Red rushes to aid Hiroto and Miu, battling Nunchaku Banki and regaining Speedor along with his newly acquired Engine Ken. The other Go-ongers arrive to support and reclaim their Engine Souls. Together with the Gekirangers, they master the Engine Ken style and combine techniques to overwhelm the engine-powered foes.

Meka uses the stolen Engine Souls as hostages and threatens to destroy them unless Jyan surrenders the Dōkokugan. Faced with the choice between the sealed Long and the lives of the Rangers' Engine Souls, Jyan chooses to hand over the Dōkokugan to save the Engine Souls. Meka then sends the Rangers back to their own world, having successfully obtained his target.

The Engine Ken style is a combat technique from the Gekijūken martial arts tradition practiced by the Gekirangers. During the film, the Go-on Wings teach the Go-ongers the basics of Gekijūken, and the two teams exchange techniques and philosophies. The Go-ongers master this Engine Ken style, combining it with their own abilities to create powerful new attacks like the Super-Super Special combo.

After the final battle and the sealing of Long Banki, Rio and Mere depart for purgatory. This is their fate after being resurrected to help fight alongside the Rangers. Their departure marks a bittersweet conclusion to their temporary return, though they leave having helped ensure the villains' defeat and the restoration of peace.

Meka pounds the Dōkokugan into an Engine Soul that has been implanted within Nunchaku Banki, creating a powerful hybrid creature. This process gives Banki access to Long's sealed power, transforming him into Long Banki, a much more formidable foe. This engineered transformation forces the heroes to combine all their newfound techniques to stand a chance against him.

The heroes combine their techniques in a Super-Super Special combo, with EngineOh G9 and GekiRinTohja Wolf powering up to challenge the enhanced villain. When that proves insufficient, EngineOh G12 and SaiDaiGekiRinTohja join the fray. Through this combined assault and the teamwork of both the Go-ongers and Gekirangers, Long Banki is eventually destroyed and resealed, while the Dōkokugan is returned to Jyan.