PK Starstorm (ＰＫスターストーム, PK Sutā Sutōmu or PK Star Storm) is the Final Smash of both Lucas and Ness in Super Smash Bros. Brawl. The character yells "PK... STARSTORM!", summoning a rain of meteorites ("shooting stars") down, striking the stage and any opponents in their way.
The move differs slightly for the two characters who use it; Lucas' meteorites rain in down in groups which point slightly inwards, dealing 14% damage each and knocking the opponent sideways. Conversely, Ness' shooting stars spread out individually in a fan-like shape, dealing 20% damage and knocking the opponent upward.
These differing properties, particularly the meteorites' direction of travel, favour Lucas on smaller stages and make Ness's Starstorm the more effective on larger ones. There are also times out of sheer luck, that players can easily avoid the stars via deft dodging, or even more so through said luck, not have to do any dodging at all, since the area where the stars fall are random. But getting hit by at least one will guarantee a wad of other stars to ensure a K.O.
 Description from the Instruction Booklet
Summon forth a shower of falling stars that delivers tons of damage to enemies.
 PK Starstorm (Ness) trophy
Ness as he calls down a host of damage-dealing stars in his Final Smash. Everyone on the screen must dodge like crazy to avoid getting hurt, but that's no easy task. This attack appeared in the Mother series, but it was Poo, not Ness, who wielded it. Perhaps Poo taught Ness the secret of the attack for use in Super Smash Bros. Brawl.
 PK Starstorm (Lucas) trophy
Lucas' Final Smash. He pulls a large group of stars from the sky and sends them smashing down among his enemies, causing damage to one and all. In Mother 3, this move was used by Lucas' traveling companion, Princess Kumatora. As Ness learned this move from Poo, Princess Kumatora taught Lucas when he learned he would appear in Super Smash Bros. Brawl.
PK Starstorm (PSI Starstorm in North America) first appeared in EarthBound and later appeared in Mother 3. In both games, the move involved using the character's psychic power to send down "stars" on enemies. However, in both games, neither Ness nor Lucas learn the move, but was instead taught to Poo and Kumatora respectively (This is explained in both Ness' and Lucas' PK Starstorm trophies). In the description for the move in EarthBound, it states that the move uses a method of "shaking off the stars". In EarthBound, PK Starstorm can deal between 270 to 900 damage. In Mother 3, the move can deal between 650 to 680 damage. Also, in both games, the move is impossible for any enemy to avoid. While PK Starstorm takes up the majority of the stage, it is possible to avoid.