The user yells "PK... STARSTORM!", calling forth a rain of meteors ("shooting stars") which pass through the stage striking any opponents in their way.
The move differs slightly between the two characters who use it. Lucas' meteorites are yellow, angle slightly inwards towards the centre of the stage, accelerate as they fall and deal 14% damage each, knocking the opponent sideways. Ness' shooting stars are blue, are angled more strongly and outwards rather than inwards, and deal 20% damage each, knocking the opponent upward. In addition, Lucas spawns a larger number of meteorites than Ness, but Ness's are slightly larger.
These differing properties, particularly the meteorites' quantity, make Lucas's damage output more consistent, but make Ness's more volatile and thus grant him higher KO potential. Due to the meteors' randomness, there can be times where they can be easily dodged or even avoided without having to move at all. Getting hit by even one meteor, though, is likely to cause the victim to be hit by many others, causing heavy damage and a likely KO.
PK Starstorm received notable changes, which apply to both of its users: it no longer covers the whole stage, but consists of a fast stream of meteors which covers a small range and whose direction can be adjusted with the control stick/circle pad, similar to Aura Storm. While a powerful attack, its small horizontal range creates blind spots. The meteors now deal flame damage, and during the attack the PK Starstorm sound effect from EarthBound plays. Between Ness and Lucas, both versions of the attack now function identically in terms of control, appearance, and damage output (including both characters having blue meteors).
The Final Smash now functions as a hybrid between the Brawl and Smash 4 variants, with the meteors being large and spawning in random positions, but the angle at which they travel can be influenced so that they are more likely to fly to the left or right of the stage. However since the spawn locations and angles are still ultimately random to a degree, the player has considerably less control than they did in Smash 4. Paula and Poo join Ness, while Kumatora and Boney join Lucas.
The differences between Ness's and Lucas's versions are much more pronounced. Ness's meteors will spawn at the top and centre of the stage, and will fly out at a range of angles, fanning outwards from an invisible "line" going down the middle of the stage. This line can be angled to the left and right, and newly spawned meteors will fan out from whatever angle the line is at the time, although the range of angles still varies significantly, limiting Ness's control over the meteors significantly.
Lucas's meteors instead spawn above Lucas, offset to the left and right, and will be angled such that they all cross through Lucas' position, and thus are angled inwards. The position that the meteors aim for can be moved both left and right, and up and down, and any spawned meteors will always cross through wherever the target position was when it was spawned, however the spawn position remains based on where Lucas is. In general, the player has more control over the path of Lucas' meteors than Ness'.
In addition, Ness's meteors are larger, deals more damage and knockback, and he spawns an extra meteor compared to Lucas, while Lucas's meteors are smaller and deals less damage and knockback, but the knockback sends at a more horizontal angle and, as stated above, the player generally has more control over his meteors.
Early meteors quirk
Ness's PK Starstorm has a strange quirk in Ultimate. The first time the move is used in a match or Training session, the camera will first zoom in on Ness as he announces the move, and then upon returning to normal, meteors will begin to spawn. A total of 16 meteors will spawn in total. However, on all subsequent uses of the move within the same match or session, 2 meteors will spawn while the camera is zooming in on Ness. These early meteors spawn in addition to the 16 other meteors, bringing the total up to 18, and can be very difficult for opponents to see due to the zoom in. In matches with multiple Nesses, each Ness must use their own PK Starstorm once to trigger the effect, and one Ness using PK Starstorm will not trigger the effect for a different Ness. Because of this, Ness' PK Starstorm is more effective on subsequent uses in a match than it is the first time it is used. It is currently unknown what causes this, or how many meteors the move is intended to summon.
In Super Smash Bros. Brawl
In Super Smash Bros. for Wii U
PK Starstorm (localized as PSI Starstorm in EarthBound) first appeared in EarthBound and later appeared in Mother 3. In both games, the move involves using the character's psychic power to send down stars on enemies. However, in both games, neither Ness nor Lucas learn the move; instead the move is taught to their friends Poo and Kumatora respectively in story events. Brawl explains the inconsistency in both Ness' and Lucas' PK Starstorm trophies, saying that they were taught the moves by their friends specifically for Smash. Super Smash Bros. Ultimate offers a new explanation by having Ness and Lucas summon Poo and Kumatora respectively during the animation.
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 and 900 damage, and is available in both "α" and "Ω" tiers of increasing strength (the latter only becoming available during the last stretch of the game). In Mother 3, the move can deal between 650 and 680 damage and only comes in a single, unlabeled tier. Also, in both games, the move is impossible for any target to dodge, but it can be reflected by sufficient PSI shields; this behavior does not translate into Smash.
Names in other languages