Diancastra is a trickster Power with many faces and wiles. Her father is Annam and her mother a giant of unspecified race (but assumed to be a storm or cloud giant). Thus, she is half-divine in origin, like Hiatea (whose birth predates hers).

Diancastra sought, as a young giantess, to claim her divine inheritance from Annam, but unlike Hiatea, she used wit and wile to do this rather than striving to perform heroic feats in battle. Several aspects of her character are revealed in mythic tales told of her youthful career. She is brave to the point of foolishness, although she prepares and disguises herself carefully. Thus, she stole a magical necklace from Blibdoolpoolp by disguising herself as a kuo-toan and carefully watching the changing of guards at the kuo-toan Power's palace. Once inside the palace, she used illusions and magical aids to swiftly grasp her prize.

Diancastra is also impudent, even arrogant. She taunts stupid but proud enemies, enraging them and driving them into snares of illusion. Her taunting of a nameless demigod servitor of Surtr allowed her to lead him through a merry dance of illusions while her magical owl stole his spellbooks, which she in turn exchanged for illusionist spellbooks with a powerful human illusionist. She added a little something to that bargain, however, which brings us to another of her characteristics.

Diancastra considerably enjoys worldly pleasures, but this enjoyment also has the happy knack of furthering her own fortunes. She drinks to excess and won a famous drinking contest at the Seelie Court (sylvan Powers), which further won her some admiration and tutelage in bardic skills. She is disposed to lavishing her favors on males who reward her with magic, knowledge, and skills. The mark she has on her shoulder comes from her rising from the watery bower of Deep Sashelas, who gave her the gift of water breathing and stretched out one exhausted hand to touch her as she left.

This aspect gives Diancastra a burgeoning role as a minor fertility patron among the non-evil giants, some of whom invoke her name if they wish their partnerships to be blessed with children. This is a double-edged invocation, though, for it is thought that it invites the birth of a cheeky, willful, naughty child. Her cult is still very small and she has no clerics. To invite one of "Diancastra's brood" into one's life is also to hazard the child being strange or fey in some way, according to giantish lore, but this may be superstition.

Diancastra travels in search of proving herself to Annam by the use of her wits in solving sphinx riddles, making solemn sages laugh with her punning and loquacity, deciphering an infamous and lethal "crossword maze" filled with cyphers by a long-dead lich-king who, in his boredom, had filled its inner recesses with magic (and elementals which had to be fought), and much else. When she presented herself to Annam, citing Hiatea's presence among the gods as a precedent for her own divine ascension, the Creator told her to circle the earth in an hour or less and he would grant this, knowing well that she had no magical talents or items to aid her. Diancastra simply retrieved an atlas of the worlds from Stronmaus' library, opened it at the appropriate illuminated page, tore it out (making the Powers gasp) and drew a circle around the picture of the earth. Annam made her a Demi Power, and it is said that he did only this because the one way back into the world for him would be for his despair to be lifted by further demonstrations of her spunk and wit. But she is still keeping him waiting, willful as she is.