(Not to be confused with PSI Starstorm)
PK Starstorm is a PSI spell only for use by Kumatora. Ionia teaches the spell to Kumatora at the end of Chapter 7. It's power is comparable to PK Love Omega. The Barrier Trio is also capable of using the move. Kumatora is unable to realize the Omega form of PK Starstorm, unlike Poo.
PK Starstorm costs 48 PP to use.
Super Smash Brothers Brawl
This was Lucas' Brawl Final Smash. How Kumatora passed it onto Lucas is a mystery. Lucas' PK Starstorm doesn't curve anywhere near as much as Ness'. Instead, it stays straight. It is better to use his attack near the middle of the field.