Eternal Queen

The Eternal Queen is the current ruler of the Kingdom of Zephilia.

She is a human, who, similarly to the Knight of Aqualord, was born with a fragment of the late Aqualord Ragradia within her soul. This seems to give her an amount of the shinzoku's abilities, which is the most apparent in her lack of (or greatly reduced) aging, which might serve as the origin of her title as well. The source material suggests that she is acting as the queen of the country since a while now, although the exact length of her rule was never elaborated upon. Unlike the knights, she seems to have inherited access to the Aqualord's knowledge, instead of possessing a greater amount of the shinzoku's magical power. (Still, she might not have the same amount of knowledge that is contained in the Claire Bible - the sources seem conflicting in this regard.)

Trivia
When planning Slayers NEXT, Kanzaka forgot to mention his concept of the Eternal Queen, and thus the anime crew created a very similar character instead. This was Auntie Aqua, who, as the manifestation of the Aqualord's remaining thoughts, is able to appear near the complete copies of (and also the original) Claire Bible.