Part :1 Tournament?
In the Dimension of the games, their is a Creator God and a Deleter God, they have discussed that they wanted to hold a tournament leaving only one Universe unharmed. They had teleported the most leading fighters in each universe, for Universe 1 it was Peach, in the second universe it was Wii Fit Trainer, in the third it was Zelda, for the fourth it was Robin and for fifth it was Villager. Sixth was Mewtwo, seventh was Palutena, eighth was Marie and ninth was Ryu. The Deleter says "There will be a Battle Royale in a day, get 10 fighters and if you lose the 10 fighters then your universe gets deleted. Here is a paper and let all of your teammates sign it to let them join your team" and teleports them back to their universes. As Peach returned she went straight to her kingdom. She told a Toad to call Mario and Luigi. As Mario and Luigi leaped in, Peach asked of them if they could join they answered with a yes. She told Mario to go get Yoshi and Bowser as she went to get Rosalina. Mario arrived at Yoshi Forest and saw his guardian Yoshi he told Yoshi about the crisis that they were in. Yoshi agreed at they both set off to the dark.
Part 2: Universe 1's Team
Peach is set off with Luigi to space. They see this colony which is… ROSALINA. She is building a society with her Luma's. Peach approaches her and says that they need her, Rosalina grabs her Luma and says "LETS GO" as they fly back to earth waiting for Mario, Peach grabs the gifted Toad and says that this would do and waits for Mario. As Mario and Yoshi are fighting the koopalings. Bowser stops them and asks why they are here, Mario responds "We need you for a tournament" Bowser rolled his eyes and said "Fine but I will be making a truce with you after that ever" as Bowser brings Bowser Jr. with him. Peach asked Daisy if she could join and she accepted and then Peach asked Birdo but he rejected it because he was busy and then Mario, Yoshi and Bowser came back signing the paper and waiting.