PK Flash

PK Flash, also known as PK Pulse, is ' neutral special move in Super Smash Flash 2.

Overview
When performed, Ness shouts "PK Flash!" and summons a green ball of energy from his head. If the special input is held, the ball will rise up for a moment and then start to lower, getting larger over time. It can also be moved left or right slightly if the corresponding movement inputs are pressed. After a few seconds, or when the special input is released, the green ball detonates, attacking opponents hit by the resulting explosion and dealing electric damage. The size of the explosion and the amount of damage and knockback dealt depends on how long the move is held. If detonated immediately, the explosion deals 8% damage and decent knockback. If held for the maximum amount of time, it deals 33% damage and massive knockback.

The projectile can travel relatively far and is not affected by contact with a platform. The move itself cancels all of Ness's momentum but also slows his descent, and it does not leave him helpless when used in the air.

Origin
PK Flash (localized as PSI Flash) first appeared in  as a move learned by Ness. There are four levels to this power, which are: α (Alpha), β (Beta), γ (Gamma), and Ω (Omega). PK Flash α and β will often cause enemies to cry, feel strange, numb, and in some circumstances, be instantly destroyed. PK Flash γ and Ω will often destroy enemies. When Ness uses PK Flash in SSF2, the player can either let PK Flash fully charge and "explode" or stop charging early for a less powerful explosion. PK Flash being weaker when less charged and most powerful when fully charged is likely a reference to the different levels of PK Flash in EarthBound.