When performing Volcanic Dunk, Knuckles jumps slightly into the air while releasing his teammates from his grip (due to holding them for the move's initial attacks). He then punches into the ground with his fist with such force that it creates powerful volcanic explosions which damage anything caught within its radius.
By collecting red Power Cores during gameplay, the player can increase the power, nature, and radius of the Volcanic Dunk. The levels of power are as follows:
Level 1: Knuckles punches into the ground and creates a slight tremor, releasing a flaming shockwave.
Level 2: Knuckles punches into the ground, which forms a bigger flaming shockwave and creates a bigger tremor. Attack radius is increased about a couple of meters and the resulting damage dealt is doubled.
Level 3: Knuckles punches into the ground, creating a powerful volcanic eruption for a few seconds which makes fireballs spew out from the ground and high in the air. The explosions the move create are capable of defeating almost any enemy they touch. Attack radius and damage is at maximum.
To perform this technique in gameplay, the player must have Team Sonic in Power Formation and must have performed the Spinning Back punch. Right after using the Spinning Back punch, the player then has to press // to use the Volcanic Dunk.
During the battle with Metal Overlord, when Super Knuckles is performing the Volcanic Dunk, he will punch continuously into the air while releasing a fury of fireballs that explode upon contact. As long as the action button is repeatedly pressed, the player can perform this attack for as long as desired.