"Mario's Revenge on Luigi!" is the 2nd video created by MarioMario54321. It is the prequel to a later video called "Luigi's Revenge on Mario!"
Mario finishes his sign and goes to look out for it. Luigi becomes jealous of Mario and destroys his sign with a Star. Mario finds out about this and immediately challenges Luigi to a duel in the Skyscraper. Mario hits Luigi with a shell and slams him when he is invincible before Luigi drives away. Luigi tries to defeat Mario, but failed when he fell down the tower.