At Bowser’s Castle, Bowser was sitting on his throne, angrily watching Mario and the heroes on his TV. Using his hidden camera feeds, he noticed that Mario had gained powerful new allies — and this made Bowser furious.
Seeing an opportunity, Bowser and the villains agree to conquer and destroy the Mushroom Kingdom with a massive alliance.
The next morning, the Mushroom Kingdom was calm. Mario, Sonic, Kirby, Steve, and the others were relaxing and talking about their recent victories. Suddenly, airships filled the sky, and Bowser's minions started pouring into the Mushroom Kingdom from every direction!
The heroes quickly got into action. Mario led a group on the ground to defend the castle gates. Sonic dashed across the battlefield, knocking out minions at lightning speed. Kirby used his powers to copy enemies abilities.
