From Sonic Retro
Volcanic Dunk is Knuckles' version of the Circular Attack move for Team Sonic in Sonic Heroes. After firing both Sonic and Tails towards enemies with an aerial Fire Dunk, pressing again will see the echidna break out this final radius-of-effect earthquake which is potentially Team Sonic's strongest bar Sonic Overdrive.
The strength and nature of a Volcanic Dunk depends on how many Power Cores Knuckles has collected:
- First level up: Knuckles punches the ground and creates a slight tremor.
- Second level up: Knuckles punches the ground and creates a bigger tremor. Attack radius increases.
- Third level up: Knuckles punches the ground and fire balls come spewing out. Attack radius at maximum.
If Volcanic Dunk is used while Knuckles is in a Super State, he will continuously punch the air, causing enemy damaging explosions with each punch. This can ultimately be done for as long as the player wishes.