PK Flash is a Special Move in the Super Smash Bros. video game series. It is performed by holding the Neutral B combination, and acts very similar to Lucas's PK Freeze. PK Flash can be used in Super Smash Bros. Melee and Super Smash Bros. Brawl by Ness.
When performed, a ball of green light appears above Ness. As the B Button is held, the ball of light moves downwards and increases in power, until the B Button is released, or until it is fully charged, at which point it explodes radiantly. The light can be charged until it falls to the altitude from where Ness initiated the attack. PK Flash can be slightly moved horizontally by using the Control Stick. The move is canceled if Ness is hit by an opponent, much like how PK Freeze is canceled if Lucas is hit while performing the move.
If the attack falls upon a platform or a higher level of a stage before it can detonate, it will disappear harmlessly. When performed in the air, it sends the user into a helpless, falling animation. Fully charged, without the influence of special conditions, it deals a maximum Damage Percentage of 39%, with huge knockback. A fully-charged PK Flash can knock-out an opponent with a Damage Percentage as low as 35%.
Unlike most of Ness's abilities in the Super Smash Bros. series, this move is the only PSI ability actually realized by Ness in EarthBound. In Super Smash Bros. for 3DS and Wii U, he appears to be using that move for one his smash attacks and his grab and throw moves because of the electricity is colored green like his special attack.
Some have commented that, due to his accent, it sounds like Ness is saying "PK Plus" or "PK Pulse".