|“||Hit opponents with a beam and launch them toward a Keyhole. Up to three opponents can be affected by the Keyhole, and if their damage is high enough, they'll be instantly KO'd.||”|
|—Description from Ultimate's Move List.|
Upon activation, Sora will exclaim "Let's go!" and fire a beam from his Kingdom Key Keyblade; the beam creates a Keyhole-shaped portal that can trap up to three opponents. It will then cut to a scene, showing the captured fighters floating aimlessly behind a door bearing the Smash symbol. As the door shuts, Sora will then fire a second beam into the door's Keyhole, and then twists the Keyblade sideways to lock it. Sora then turns to the camera to strike a pose as the door explodes before cutting back to normal gameplay view. Any trapped opponents that have over 100% damage after this Final Smash are instantly KO'ed.
Sealing Keyholes is a major narrative element in the first Kingdom Hearts, where Sora, Donald, and Goofy, are tasked with traveling to several worlds to seal their Keyholes during their quest to find Riku, Kairi, and King Mickey. Within the story, Keyholes are the gateway to the world's heart, and if destroyed, the world will crumble and fade from existence; the Heartless were sent out by Maleficent to break into a world's Keyhole and devour its heart. Such a situation occurs in the beginning of the game, where the Heartless destroy the heart of Destiny Islands in their search for Kairi, one of the Seven Princesses of Heart, and effectively separate her, Riku, and Sora from each other. After meeting with Donald and Goofy in Traverse Town, a refuge for denizens that have already lost their worlds to the Heartless, they take it upon themselves during their search for their friends to save the other worlds by sealing their Keyholes, something only possible by a Keyblade wielder.
Near the end of the story, it is revealed that Maleficent and her associates were creating an artificial Keyhole in Hollow Bastion using the hearts of the Seven Princesses; this Keyhole would lead to the location of Kingdom Hearts, an area where the heart of all kingdoms reside and is said to be a source of immeasurable power and knowledge. Sora inadvertently completes its creation after freeing Kairi's heart that had been hiding within him since Destiny Islands' destruction, allowing Ansem, Seeker of Darkness (who had possessed Riku) to enter through it to arrive at the End of the World, a place of darkness formed by all of the worlds destroyed by the Heartless. Sora ultimately battles Ansem inside to prevent him from finding the Door to Darkness within, a door that leads into Kingdom Hearts' location; though he prevails, Ansem tries entering into the door anyway, only to be destroyed by the light from within. Sora, Riku, and King Mickey then seal the door from both sides, restoring all destroyed worlds (including Destiny Islands) in the process. It is presumed that all of the restored worlds had all of their Keyholes sealed and hidden, preventing another destruction. As such, future games no longer revolved around finding and sealing Keyholes.
- Sealing the Keyhole is one of two Final Smashes that can end with a Special Zoom, the other being House of Boom.
|Sora's Special Moves|
|Side Special||Sonic Blade|
|Up Special||Aerial Sweep|
|Final Smash||Sealing the Keyhole|