PK Flash is a spell only available for Lucas. It is learned in Thunder Tower after Lucas is struck by lightning. PK Flash is used for causing status effects. It can cause either Crying, Numbness, Strangeness, instant incapacitation, or absolutely nothing. PK Flash has no stage, unlike Ness' PSI Flash, which can be maximized to PSI Flash Ω. This is a downfall for Ness can increase the chance of instant incapacitation unlike Lucas. By using the Ω level, the rate of instant incapacitation for Ness is increased.
Crying has the highest percent of success, with 60%, while doing nothing has the lowest with 5%.
PK Flash can be used to cause a useful status effect. It is also one of the two ways to defeat the Porky Statue, although it isn't very effective against it.