What if Bowser won the final battle in Super Mario Galaxy? After defeating Mario, Bowser sets out to conquer the universe. Meanwhile, Rosalina tasks Luigi with finding a way to rescue Princess Peach and save the universe. But can he do it without his loyal brother? Or is the entire universe doomed?

What if they could stop the Calamity from ever happening? What if they could stop all of the Calamities from happening? When Zelda finds a book from thousands of years ago describing a curse placed on her and Link, she begins to wonder if there's a way to stop the curse from ever occurring.