,,Guided by Warm Light in this Galaxy! I am SaIor Theia, Soldier of Brightness and Hope!"
Sailor Theia or her real name Serafina Serenity is the first one of the Royal Family of the Moon and the first Senshi to guard it. Her Star Seed is Heart Moon Crystal and helds more power than Silver Moon Crystal ever had.
Long ago, when the Universe was young, the Moon was a more bigger planet, Theia. The Royal Family here had only one daughter, named Serefina Serenity. One day, another planet crushed Theia making it a mass of floating rocks, kiliing everyone. She was saved by a unknown force becuase she didn't fullfill her destiny. At that moment, a crescent moon symbol appeared on her forehead, transforming her into Sailor Theia.
The pieces of Theia sooon formed a new planet, the moon that we all know. She became the queen of this new, bright planet and revived the people of Theia.. She builded the Moon Kingdom and the Silver Millenium, in the middle of Mare Serenitatis. when a comet was heading towards the Moon she sacrificed her life to save her planet. Her daughter made a great shrine in her honor before ascending to the throne.
She was named after a planet who exploded and formed the Moon and the Titaness in the Greek Mithology who was the mother of Selene, the godess of the moon.