When triggered, Sandbag will suck up the nearest character, blast off towards the Home-Run Contest stadium and create a "negative zone". Then, he combos the opponent, using a up tilt and a back aerial. Afterwards, he grabs a Home-Run Bat and proceeds to hit the opponent with the item, launching them away. The distance counter gets broken after a few seconds.
Revenge is the crux of the joke behind Sandbag's character, in that he himself is usually the target in Home-Run Contest and is now returning the favor to those responsible.
The highest scores in the mode are attainable by performing steady combos within the confines of the small platform, which Sandbag does automatically. The method how he goes about it, however, is an external reference to JoJo's Bizarre Adventure; specifically, to the character Dio Brando and his own ability to stop time, marked in the series by inverted colors. Additionally, the animation that plays just before smashing his opponent is an external reference to Fire Emblem: Awakening; specifically, to the near-identical animation that plays when a character gets a Critical Hit.
From Beta 1.0.0 until 1.0.2, the animation used a very old Home-Run Bat texture, with two red lines and a red circular logo resembling a target, whereas the Home-Run Bat in v0.9 used a different texture, with two brown lines and a different logo, also brown.