In the manga, Chaos is depicted as a being trapped within the Galaxy Cauldron, having missed its chance to become a star. It manifests through incarnations that serve as Sailor Moon's primary adversaries, including Queen Metaria, Death Phantom, Pharaoh 90, and Queen Nehellenia. Eventually, it manipulates Sailor Galaxia into stealing Sailor Crystals to free itself and dominate the galaxy. Chaos appears as an immense mass of black, fourth-dimensional space. Ultimately, Sailor Moon forces Chaos back into the Galaxy Cauldron, allowing those who were killed to be reincarnated on their respective planets and in their original times after the battle. However, it is hinted that Chaos survives and will return as Sailor Chaos, similar to what occurred in Sailor Cosmos's future.
Sailor Chaos is Chaos reborn as a powerful Sailor Senshi. According to Sailor Cosmos, Chaos will emerge from the Galaxy Cauldron with renewed strength. Frustrated by the endless conflict against Sailor Chaos, Sailor Cosmos disguises herself as Chibichibi and travels back in time to persuade Sailor Moon to destroy the Galaxy Cauldron, thereby preventing Sailor Chaos from rising and initiating another series of devastating wars.
In the anime, Sailor Chaos does not appear, but Chaos makes a brief appearance in episode 200, expelled from Sailor Galaxia after her defeat. Apart from this, Chaos does not feature prominently in the anime. Sailor Galaxia ultimately reveals herself as the warrior who sealed Chaos within her own body, thus saving the galaxy. Chaos possesses Galaxia to grant her the power to confront the Light of Hope—Eternal Sailor Moon. However, Usagi manages to awaken the remaining hope in Galaxia's heart, causing her to expel Chaos from her body and bringing the anime story arc to a close.
