Aidios (空の女神 エイドス Eidos) is the Goddess of the Sky and serves as the religious entity to the Kiseki Universe. Aidios gave ancient humans seven artifacts of power known as the Sept-Terrion, one of which was the Aureole, the Shining Ring used to power the Liber Ark. Throughout the world of The Legend of Heroes: Trails in the Sky, the most common and influential religion among the people worship Aidios. They worship Aidios with churches within each city for prayer similar to Christianity.
- Aidios in Greek translates into 'eternal'.
- Aidios is similar and is pronounced the same way to the Spanish phrase "¡Ay Dios!" which translates to "Oh my God!"
- The English version of Trails in the Sky changed "Eidos" to "Aidios" due to copyright issues since "Eidos" is the same name of another video game company.
- It is speculated that she is the leader of Ouroboros