When using this special technique, Mario and Luigi jump into a window, which teleports them close to a random opponent. The windows will appear at different orientations depending on which enemy is the target. As Mario or Luigi jump out of the window, the player has to decide which button to press: for Mario, for Luigi, or press both of them. If the player fails a button press, the attack will end. This attack costs 18 SP to use.
This attack is unlocked by defeating the optional Shroob boss. The shape of the window itself seems to be modeled after the Shroob Empire symbol used in Mario & Luigi: Partners in Time, where the Shroobs were major enemies.