After Mario rescues them, they give him a special power called Star Beam, which is used to neutralize the effects of the Star Rod, and a ship that they can use to travel to Bowser's Castle. During the final battle with Bowser, due to the effects of Bowser's Power Platform, their Star Beam does not work against him, unless Star Beam is upgraded to Peach Beam when Twink helps Mario out in the battle.
The Star Spirits reappear in Mario Party 5, where they are known as Star Guards and guard the Dream Depot and all of its dreams; in addition to slightly updated appearances, their mouths are also no longer visible. They guide the players throughout the game as well. They return as a collectible for Mario Party 5 in Mario Party: The Top 100, where they are once again known as the Star Spirits.
The Star Spirits' Names and powers
After Mario rescues the first star spirit Eldstar, he gains a natural ability to Focus. Focus boosts Star Energy.
Negates the effects of the Star Rod. During the final battle with Bowser, Star Beam has no effect against the Star Rod due to the device. Kammy Koopa made. After Princess Peach and Twink defeat Kammy Koopa, this power is upgraded to Peach Beam.
Duties in Mario Party 5
Eldstar: Guide of the party mode.
Mamar: Guide of the bonus mode.
Skolar: Guide of the super-duel mode.
Muskular: Guide of the minigame mode.
Misstar: Guide of the story mode.
Klevar: Explains the game modes, and hosts some events on boards when stopped at a Green Space.
Kalmar: Guide of the options mode.
Official profile from Mario Party: The Top 100
Dream Depot Star Spirits: "Star Spirits from Star Haven that guard the Dream Depot, a dreamy world found far away in the starry sky."
The Star Spirits, Goomboss, Whacka, and the Koopatrols are the only characters to originate in a Paper Mario game who make later appearances in 3D Mario games.
In the North American release of Mario & Luigi: Paper Jam, Starlow erroneously refers to herself as a representative of the Star Spirits, when she is actually a member of the Star Sprites.