The trailer opens up on the Mii of the Mii Swordsman in a suit, on the set for Mii News in Tomodachi Life. He's talking in the regular monotone Mii voice, informing the audience about the recent darkening of the sky over the island, and how it's been going on for a week. He goes to the interviews (like in the regular Mii News) and the first Mii pops on screen. The background is noticeably darker, as if it were nighttime. The Mii on camera starts to talk but is interrupted by being jumped by Bowser, who proceeds to lift said Mii up. Orange pellets are shot at Bowser from off camera, and he flies away. The scene naturally cuts back to the Mii New Office where it is empty, the Swordsman is gone. The scene goes outside to where you see the Mii Swordfighter in his Smash Gear running towards Bowser from the Mii News Offices. Bowser is getting up when the three Mii Fighters all reach him. A small white ball flashes in between them and Bowser, which quickly snaps into Mewtwo (he used teleport). Mewtwo blasts the three Miis away, and his title card shows. He laughs and it cuts back to the Miis, who are trying to get up. Mario, Link, Kirby, and Pikachu jump in front of the Mii Fighters to stand in between them and Mewtwo. They all stop when the sky starts rumbling. The dark clouds all disappear, as Bowser's airship is flown in by Ganondorf. His title card is displayed, and he jumps down from the airship, landing perfectly fine. He runs at Link, and they break off into a one on one battle. Mario goes after Bowser and Pikachu goes against Mewtwo (one on one battles). The screen pans to Kirby, who has nobody to fight. He runs to help the struggling Link, but is stopped by Meta-Knight who swoops in and slashes at Kirby, causing him to get hit away. Meta-Knight's title card is shown and he flies at Kirby, who is now ready to fight. The screen goes back to Link and Ganondorf, who are still fighting furiously. It seems like Ganon has the upper hand, and he grabs Link and throws him on the ground, the master sword skidding away. Ganon looks as if he's about to finish it, when he is hit by Toon Link's bomb, saving Link. While Ganon is stunned, Toon Link jumps at him to try to finish Ganon, but is held in the air for a bit, and then thrown the opposite direction. It is revealed that Vaati did this, who gets his title card shown. Meanwhile, Pikachu is failing against Mewtwo, who is blasted back by Thunder, and he decides to Mega Evolve. He becomes Mega Mewtwo X, and dashes at Pikachu with increased speed. Jigglypuff slams into Mega Mewtwo X using Play Rough, which blasts Mega Mewtwo X backwards. Pikachu and Jigglypuff have a friendly greeting (c'mon they're Pokemon, they have to
). Mario is completely beating Bowser, but is punched out by Wario, who jumps in to help Bowser. Kirby and Meta-Knight seem to be having an even fight, but at one point Meta-Knight gets the upper hand and kicks Kirby over. He swoops down from the air to finish Kirby (that looping move from Brawl he had) but it grabbed by a beam of blue light. The beam belongs to Samus, who arrives just in time to save Kirby. The rest of the Original 12 have shown up at this point (even if they weren't shown) and they all form a line side by side (the Miis left after they were defeated). The villains line up, too. Mewtwo lifts Samus with psychic, but is shot away by Ness. Mewtwo and Ness go into an in-depth psychic battle against each other. The others go to try to attack Mewtwo, but they are easily prevented by the villains. Samus, charging her charge shot, runs towards Ganondorf who has Link pinned down. She aims to shoot Ganon, but is roughly grabbed and misses the shot. She is thrown into the air where she sees that Ridley threw her upwards. Ridley screeches and his title card shows. He flies at Samus who fires a missile at him. There's an explosion and the screen fades to gameplay of the villains beating up the heroes in Smash 4.