Saintia Sho : Cassiopeia Elda is a short-haired Saintia wearing the Cassiopeia Bronze Cloth who wishes to one day become a Gold Saint.
Lost Canvas : The Cassiopeia Saint is an unnamed Saints who appears briefly only in the anime adaptation, forming part of Athena’s army led by Sagittarius Sisyphos in the attack to Hades’ castle.
Cassiopeia’s story originated in the mythology of ancient Greece. Cassiopeia was the queen and consort of King Cepheus in Ethiopia. Cassiopeia was a great beauty and was extremely vain as a result; she proclaimed she was more beautiful than the Nereids, the 50 nymph daughters of the sea god Nereus. However, hearing this boast, the Nereids complained to Poseidon, especially as his own wife, Amphitrite, was one of them. To punish Cassiopeia for the affront, the god sent the sea monster Cetus to devastate the kingdom. When Cepheus consulted an oracle to find out how to stop the monster, Poseidon demanded Andromeda, the king’s daughter, as a sacrifice to Cetus to end the bloodshed.
The hero Perseus, returning from having slaughtered the gorgon Medusa, encountered Andromeda lashed to the rocks awaiting her death and fell in love with her. He spoke to Andromeda’s parents and struck a deal with them: he would free Andromeda and stop Cetus in exchange for the princess’s hand in marriage. Perseus defeated the monster using Medusa’s severed head, freed Andromeda and returned to the city.
However, prior to being sacrificed, Andromeda had been engaged to marry Phineus, the brother of Cepheus, who demanded his right to wed his niece after she was saved (in Ancient Greek culture, a girl with no brothers could be engaged and married to an uncle by her own father).
In some tellings, Cepheus and Cassiopeia sided with Phineus, who came to fight Perseus with a band of men for Andromeda. Outnumbered, Perseus used the head of Medusa again to turn Phineus and his followers to stone (which included Cepheus and Cassiopeia). After death, both Cepheus and Cassiopeia were placed among the stars as constellations; Cassiopeia retains her vanity beyond death, depicted as a reclining woman gazing into a hand mirror. As a penalty for being so self-absorbed, Cassiopeia’s constellation flips upside down for half the year, an actual astronomical phenomena.