The Power Flash is one of Knuckles the Echidna's special attacks in Sonic Adventure 2 and its remake Sonic Adventure 2: Battle. When using it, Knuckles immobilizes his opponent for a short amount of time.
When performing the Power Flash, Knuckles thrusts his right fist forward and shouts "Take that!" He then releases a flash of light that disables his opponent's movements for a short time. The opposing player's screen will be covered in a pink tint and a counter counting down from ten will appear. This effect leaves the opponent completely immobilized, making it an ideal way for the user to gain the upper hand in collecting Emerald Shards. The Power Flash lasts for ten seconds, which is indicated by the counter, although the opposing player can reduce the amount of time remaining by rapidly pressing buttons.
The Power Flash can only be performed by playing as Knuckles in the games' two-player mode. To use it, the player must press / on the ground after collecting sixty Rings. To use it again, the player has to collect another sixty Rings.