In my fanfic, Theia and Hyperion are the names of Queen Serenity's parents. Hyperion, however, is also the name of Celeste's older brother. I'll go further into this whole thing later on when the characters are better developed.

*         Anyway, Serenity is suppose to be based on the moon goddess Selene. Serenity is the oldest of three siblings (in my fanfic; in mythology I have no idea who is the oldest).
*         Anyway, Dutchess Clarice (Queen Clarity) is suppose to represent the Sun. The name Helios was already taken in the Sailor Moon universe. But anyway, this is why Celeste, Clarice's daughter, is the Solar Sailor (after Sol, another name for the Sun). The reason I call her Clarity is because she is able to see things so clearly.
*          Also, though not mentioned in the fanfic yet, there is a third daughter of Theia and Hyperion, Eos. She is suppose to represent the dawn and is the youngest. Since Selene is the Greek name, I thought I'd stick with the Greek names for consistency in this case.