Beatrice (ベアトリーチェ Beatorīche?) is the main antagonist of Episodes 1-4. She clashes with Battler Ushiromiya, trying to convince him that witches are real and that she used magic to execute a series of bizarre murders on the island of Rokkenjima.
She has claimed to have lived for well over a thousand years. She has already strayed from the domain of humans, and it is said that as demons do, she appears when summoned by a human and lends him her power for a compensation of equivalent value. She likes black tea and ice cream and hates boredom and people who deny her.
Beatrice appears as a Western-style woman with ginger-blonde hair and blue eyes. Beatrice has many different appearances. Her witch form wears a bow adorned with a rose in her hair, a choker, and ballgown-like dress. Her dress constantly switches from brown to dark brown across the different adaptations, appearing brown in both the anime and PS3 game, while the dark brown in Ougon Musou Kyoku and the original visual novel. She also wears the successor ring on her left middle finger. She is also sometimes seen holding a gold kiseru. In Ougon Musou Kyoku her outfit has a ribbon added to her lower back. In Pachi-Slot Umineko no Naku Koro ni, she has long nails polished red.
Her human form wears a collared shirt with a cropped jacket and tie, a ruffled miniskirt, striped stockings, and boots and usually holds a cane with an eagle head as the handle. In End of the Golden Witch, she is seen as her witch form, but with her hair down. In Dawn of the Golden Witch, her "chick" form is seen as her witch form, and her "elder sister" counterpart is seen as her human form.
Beatrice is quite a controversial character. On the front, Beatrice is a very cruel person, who loves to torture and kill people just for the sake of fun, a being so terrifying that even in the Meta-World she is feared from heavens to hell as one of the cruelest witches ever. She is at times very composed and majestic, and at other times very disgraceful and insightful with a creepy laughter and a demonic smile.
However, as the saga goes on, more sides of her character are revealed. She proves to have a very joyful attitude and quite a childish side. She is in fact described by her teacher as a naive child who loves to play with toys without the fear to break them and also with a power so big that she hardly realizes she can handle. She shows this side primarily with Virgilia and Ronove which have a very parent-like attitude with her and less with Battler which she'd feel embarrassed with to act so. Quite common is, in fact, to see her sobbing on Virgilia's chest when things don't go her way.
In Episode 3, Beatrice's fantasy-laden interpretation of her own background is that as a child, she was referred to as "Princess". On a certain day broke the vase of an unnamed master. Virgilia, the current Beatrice at the time helped her by fixing the vase using her magic. Fascinated, "Princess," asked Virgilia to become her apprentice and she eventually received the titles Endless and Golden Witch. Beatrice claims that afterward, she lived for centuries and met Kinzo, who fell in love with her and sold his soul to her for 10 tons of gold. Because he loved her so much, he sealed her in a cage of flesh and was released when it was destroyed by Rosa.
In reality, the real truth behind that flashback is that Beatrice is actually the lonely servant Sayo Yasuda, who broke a vase one day and was afraid of being scolded by the Master, Kinzo. Just then, Kumasawa arrived, and told everyone that she saw a stray cat do it. Sayo, who thought of Kumasawa as a mother figure, was really happy and impressed, and Kumasawa joked to say that it was 'magic' - painting a false truth over the real one to make people think that it was a cat who broke it, not Sayo. Since then, Sayo has been interested in 'magic' and frequently plays light-hearted pranks on the other servants to make it seem like a 'witch' did it.
In Requiem of the Golden Witch, we see that Beatrice is the evolved form of the second prototype Beatrice of Sayo's witch persona and that the girl whose childhood we saw in Episode 3 was the childhood of Sayo herself. The change was based on the Beatrice portrait displayed in the main hall in 1984. Sayo, in her Beatrice persona, solved the epitaph and Genji gave her the black dress that Sayo's mother once worn. After wearing the dress, Sayo was brought to Kinzo, who apologized to Beatrice and reveals to Sayo that her real name is 'Lion'. Kinzo then dies afterward, and Sayo inherited the headship of the Ushiromiya family and 10 tons of gold, to which Sayo declines, but decides to keep the dress and the gold.
Some point after the aforementioned events, when Shannon was doubting her relationship with George, Beatrice gave her a golden butterfly brooch in return for destroying the mirror in the shrine. She and Shannon would often have tea together. She also befriended Maria, who later became her apprentice. Together, they created Ronove, Virgilia, the Stakes of Purgatory, the Chiester Sisters and Sakutaro. They also founded together the magical compendium Mariage Sorciere. She would also perform magic for Maria in front of Doctor Nanjo, Kanon, Shannon, Genji and Kumasawa. However, she wanted to create a universe with Battler, not Maria. At some point after these aforementioned events she created an uncertain amount of forgeries which all set her as the culprit. Her only known forgeries were Legend of the Golden Witch, Turn of the Golden Witch and finally, Land of the Golden Witch, which was never revealed as it became lost at sea. In 1986, Beatrice puts into motion the Rokkenjima Massacre.