When used, the Mii Brawler rises into the air while unleashing a flurry of rapid punches above their head. It is very similar to the Rising Uppercut, though with better vertical recovery. This attack additionally has a sweetspot in the form of the very last hit, which can KO foes at relatively low damage percentages, particularly if they are close to the upper blast zone.
Before the game was updated to version 1.0.6, the base knockback from this move's first hit was high enough to OHKO the lightest characters in Smash 4, and since the move can be initiated from a down throw combo at low percentages, the Mii Brawler could pull off zero-to-death combos against characters like Rosalina. Despite the nerf and rare use of Miis in tournaments, Piston Punch is among the most feared of Mii Brawler's moves, as it is still capable of KOing at low percentages when used against foes high in the air, similar to how alternative up special Helicopter Kick can KO foes near edges at low percentages.
Special Move customization was added in Super Smash Bros. 4. These are the variations: