The Japanese light novel The Holy Grail of Eris (Erisu no Seihai), written by Kujira Tokiwa and illustrated by Yuunagi, had its anime confirmed this Sunday (20).
Therefore, and by all indications, the anime's premiere should happen sometime in 2025.
Synopsis The Holy Grail of Eris:
Connie, a simple and ordinary young viscountess, is saved from a difficult situation caused by the mistreatment of a wicked noblewoman by the ghost of a mysterious woman. This spirit is Scarlet Castiel, a duchess executed ten years ago who became known as a legendary villain! As a form of retribution, Connie finds herself compelled to discover who was truly responsible for sending Scarlet to her execution. However, while conducting secret investigations, entering into a fake engagement, and even confronting powerful nobles, she begins to unravel a conspiracy far greater than she ever imagined…
The online serialization began in October 2017 on the user-generated novel website, Shōsetsuka ni Narō. It was later acquired by SB Creative, which published three volumes from November 2019 to October 2020 under the GA Novel imprint.
Finally, a manga adaptation with art by Hinase Momoyama has been serialized online by Square Enix's Manga Up! website since November 2019.
Source: Official Website