- "Oh, I am yet one of many!"
- — Clair's Monologue
Clair Vaux Bernardus (クレル・ヴォーブ・ベルナルドゥス Kureru Vōbu Berunarudusu ) was created by Bernkastel to narrate Requiem of the Golden Witch and serves as a vessel for Sayo Yasuda. She is a reader similar to the role Ange Ushiromiya performed for Featherine Augustus Aurora during Dawn of the Golden Witch. She is a "substitute actor" without a personality that acts as a vessel to personify both Beatrice and the rules of her game, as Beatrice does not exist in the world presented by Bernkastel. Her name signifies that she is the final guide of Beatrice's game. She can be considered a tool rather than a person, allowing Sayo to confess to Willard H. Wright, Lion Ushiromiya, and Bernkastel without revealing Sayo's own "pitiful form." She exists only in the Meta-World and doesn't appear within the game board.
Clair is also the original form of Sayo's Beatrice, who is made to match the image of a ghost that haunts Rokkenjima with a pure white dress and contrasting personality. Once Beatrice accepts the love for Battler Ushiromiya, her form changes to match Battler's ideal woman and the portrait of Beatrice later placed in the mansion.
- Sayo Yasuda - vessel of (during Requiem)
Clair has the form of Beatrice, thus possessing the same face and expressions as the Golden Witch. However, she has white hair and a white dress to match the image of a ghost haunting the mansion during the night.
Clair Vaux Bernardus is a reference of St. Bernard of Clairvaux, the final guide of Dante, in Dante Alighieri's Divine Comedy; Beatrice and Virgilia's names refer to Dante's guides preceding St. Bernard, Beatrice and Virgil. Clair's name and role as portrait artist additionally allude to portrait artist Claire Delisle, the professional name of Eleanor Rulapaugh, the wife of art critic and writer Willard H. Wright, known also by the pseudonym S.S. Van Dine.
After Will exposes the truth about Lion, Bernkastel invites Clair to expose the truth about Beatrice and how she became the Golden Witch. She exposes eveything on stage (along with Furfur and Zepar) as all the Theater Witches watch the show. The story goes from the birth of Sayo, to the child's days as a servant until Sayo solved the epitaph. Clair (as Beatrice) is seen like a counterpart of Lion; Beatrice will not reach a happy ending, so she asks Lion to live a happy life for all the Beatrices. Lion swears to be happy for her too. Since Battler found the truth out too late, he has not come to this funeral and so Clair entrusts her final moments to Will. Will destroys her illusion and lets her rest in peace.
In the tea party, she is shown on the stage once again as Bernkastel shows her that her only hope for happiness (represented by Lion's life) will be destroyed, as the murders on Rokkenjima will take place in this fragment, as well and Lion will be killed by Kyrie Ushiromiya. Bernkastel calls this her final revenge for the humiliation she had in the previous two games as she cuts open Clair and pulls her guts out of her body.
- Clair's design may be based off the Shiro Lolita fashion trend in Japan as her outfit is very remniscent of the style. Her outfit features a maid headpiece, a white dress and bows, along with laced boots that are popular in Shiro Lolita.
- "Love is an illusion. However, if both sides are seeing the same illusion, the love becomes true. However, when the feelings of each side are different... then it’s nothing more than a joke."