Tia

 is a character in. She is the mysterious cross-dimensional equivalent of Orlha. Her origins unknown, she was stated by Orlha to be her younger sister, born to the same family and separated when the dimensions split in 1010 A.D. Her life an equal enigma, she fell into a coma around 1020 A.D. and could not be woken. Eventually, Orlha came with Serge and visited her; Tia mentioned that she was grateful to have finally met her sister, and noted that her spirit would always be with Orlha. She then passed on to death; Orlha lamented her fate, though Tia soon reappeared and comforted Orlha, allowing her to learn her final technique, SisterHoods. The technique summoned Tia to attack with Orlha in an offensive. Tia also gave Orlha her piece of the Sapphire Brooch, allowing it to become a Blue Brooch.

The nature of Tia's existence is a mystery, since Orlha apparently never met her. Apparently, Tia was duplicated from Orlha when the dimensions split, but retained her own identity. The enigma regarding these two sisters continues to go unsolved.

Another possibility is that their fates simply deviated in the two dimensions like so many others. In the Home World Dimension, Tia and the sisters' mother remained in El Nido while Orlha traveled to the mainland with their father. In the Another World Dimension, it was Orlha and their father who remained in El Nido while Tia travelled to the mainland with their mother.

Etymology
Of Portuguese origin, the name Tia means "aunt". Which dovetails with her peculiar relation with Orlha.