The Soul Star is shown to have a poor temper, and is easily angered by Switch and Megar throughout their journeys. In battle, the Soul Star can summon pink lasers which are apparently powerful enough to send its targets flying; despite this, she never actually assisted in any fights.
In “Breaking the Sound Barrier”, Dark Switch stole the Soul Shard (which the Soul Star was living inside of) and used it to revive Dark Cloud. To prevent further action from being taken, Megar shattered the Soul Shard and unknowingly released the Soul Star, who was resting inside. In a fit of rage, the Soul Star blasted Dark Cloud and Dark Switch off-planet. She then tasked Switch with recovering the lost pieces of her cocoon. After all five pieces were recovered, the protagonists faced off against Zerospace. Upon its defeat by the newly-revived Cloud, Zerospace exploded into a black hole, which the Soul Star was able to suppress (seemingly dying in the process).
The Soul Star appears again in Season 3, having apparently survived Zerospace’s last-ditch attack. She is revealed to be one of the Seven Sages of the Dream World, and used her power to stop Spectra from recovering energy. In the finale, Cloud invited the Soul Star to stay at the Observatory, but she was never seen afterward. Whether she did in fact stay at the Observatory is unknown.