Sagax

The Legend of Sagax grew in popularity as it was mentioned in the fairytale written by Jin Si in the 1950s called "The True Mountain Sage" though it was the first written account of the legend, it has been a children's tale to either scare or reassure children in the night.   Legends say of an all-seeing immortal sage that knows the past, present and future, not only that they have the magical ability to heal villagers and vanquish monsters. Though it's an asian folk's tale, there were accounts of miracle healing in the 8th century in Britain which made their view on magic become just a little positive, some say it has been in Europe in the middle of the 9th century, some say it's the sage that killed witches. A seer has revealed a term called 'Sagax' to a King once after seeking council hence the name.   Asian mythology however just calls her a sage (智者, 聖人 zhì zhě, seijin) these historical accounts have always portrayed the sage as male, but "The True Mountain Sage" portrayed her as a woman in disguise or a gender neutral, mistaken as a man due to her masculine figure for living up in the mountains and her intellect that is less associated with women than in men and for the fact that many Japanese and Chinese men had long hair.   It has been adapted into an anime and manga in the early 2000s called "Tetsujin" and a remade 2021 version was made in honor of Starn as she revealed it was her favorite manga series.  

Gretal's View

Sagax is their persona whenever they are feeling mystic or need an excuse as to why they knew many things or why they should trust them because Sagax is so popular in the East, they didn't made it themselves, it may have originate from Lady Wang's nephew telling stories about them, the more grounded side at least seeing as he didn't see them in their true form.