Sonic and Kirby team up to defeat all bosses and come up victorious. Then, after defeating Master Hand & Crazy Hand, during the post-game credits, Sonic turns Super Sonic via the Chaos Emeralds and Kirby flies using the Warp Star. After said credits, the screen fades to black. Kirby takes a walk through tall grass and sees S.S. flying in the sky. Kirby waves.
Announcer: Congratulations!
#SSBU #idea