Calliope the daughter of Harrier of the Rex Guardians and the navigator of the Sprites. She bears a striking resemblance of the female member of the Rex Guardians (possibly her mother) with tanner skin and blue eyes.
Unlike her family (mostly her father), Calliope thinks of herself as honorable but doesn't do things exactly by the book and tends to stray from tradition, causing her to leave Terra Rex. She likes to go by two rules of her own "Save lives and kick bad guy tail" both of which she excels at. She is friendly but is rebellious to higher authority.
She uses owns an energy staff powered by a yellow energy crystal.
Trivia:
Calliope's name means beautiful-voiced.
She is the first child of the Rex Guardians to be introduced.