PK Flash

PK Flash is a special attack that can be performed by Ness. It is a chargeable Neutral B attack. When the move is initiated, 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. The ball of light is arguably easier to control in Brawl than it is in Melee. PK Flash can be charged until it falls to the altitude from where Ness initiated the attack. It can be slightly moved horizontally by using the control stick. If the attack falls upon a platform or a higher level of a stage before it is detonated, it will disappear harmlessly. When performed in the air, it puts Ness into a helpless falling animation. Fully charged, without the influence of special conditions, it deals a maximum damage of 39% with huge knockback. Due to Ness's accent, many players think he says "PK Cross," "PK Frost," "PK Pop", "PK Crush", "PK Pulse" or in a smaller extent "Cut it Close" when he does this move. However, when Kirby copies Ness's PK Flash, he clearly says "PK Flash" when he uses it.

Origin
PK (or PSI) Flash is one of Ness's unique moves in EarthBound. At its lower levels, it can only deal minor effects like crying and colds, but at the Ω level, it is capable of delivering one-hit KOs to all enemies. It, along with PSI Rockin', is the only PSI move unique to Ness.