Naga, aka: Nahga (in some translations), Naga The White Serpent, Gracia Wil Tesla Seirune

Naga is the long lost sister of Amelia Wil Tesla Seirune, princess of Seirune, the White Magic capital of the world in the Slayers Universe. Naga left home when she was very young, taking her mother's outfit with her. Seeing how short Amelia is, this could explain why she wears such skimpy leather over such incredibly large breasts. In Slayers volume 5, episode 4, Amelia sees Naga walking down the street and comments on how her outfit looks just like the one her mother used to wear. In the final volume of Slayers TRY, Amelia also comments on the way that Lina Inverse laughs, saying that it's really scary, which also happens to be the same way that Naga laughs. Lina learned the summoning spell Zelas Gort, a jellyfish summon, from Naga and uses it in volume 2 of Slayers NEXT.

Naga herself prefers to use ice magic and summoning magic. Most of her summons turn out to be useless, such as the jellyfish and the stone dragon with a uniquely disproportionate head. Naga claims to be Lina's rival, but usually she just tags along and helps out.