[La Signora], the Eighth Seat of the Fatui Harbingers, originally named Rosalyne-Kruzchka Lohefalter, was from Mondstadt and roughly five hundred years old. Her original Vision was Pyro, and she was known as the [Crimson Witch of Flames].
Unfortunately, this witch had absolutely nothing to do with the renowned [Hexenzirkel] founded by Alice. In the end, she simply lacked the standing to receive an invitation from Alice.
Rosalyne was a magical genius of the sort Mondstadt rarely saw even once in a hundred years, and she had even traveled to Sumeru to study. Unfortunately, while she was studying abroad, the dark calamity of five hundred years ago descended. Mondstadt suffered devastating losses in that disaster, and most importantly, Rosalyne's lover, the knight Rustam, died in battle as well.
When she returned to her ravaged homeland and learned of Rustam's death in battle, she was so overcome with grief and rage that she shed every last tear and drop of blood in her body. In their place came endless flames as searing as molten iron.
It was also for this reason that Rosalyne was deeply hostile toward the Anemo Archon, Barbatos. She believed that, as Mondstadt's Anemo Archon, he had failed to protect Mondstadt, indirectly leading to her lover's death in battle. When La Signora had plunged her hand into Barbatos's chest back then, she had definitely been venting her anger.
A human body could never endure this flame of life that burned its own bearer as fuel for long. If it were allowed to keep burning, forget living for five hundred years-even surviving another five days would have been questionable. It was at that moment that the first Fatuus appeared before her and introduced her to the Tsaritsa.
The Tsaritsa bestowed upon her the authority of Cryo, suppressing her ever-burning flames.