Daddy Dearest sent BF and GF to the Mushroom Kingdom
Wouldn't be the first time he sent the two into the world of a videogame. However, he did not intend for GF to be kidnapped by Bowser. So should Daddy Dearest find out, he'll make a surprise appearance during BF and Bowser's duel and challenge the latter to a song where you play as him.
Mario will be Promoted to Playable in a bonus song or week.
Fair to assume considering the same thing happened with Sonic in Friday Night Funkin' HD.
