Japanese: ビリユイ
Romanji: Biriyu
Aliases: Yui Bidou
Residency: Tokyo, Japan
School(s): Mugen Academy

Member of the Witches 5


Professor Souichi Tomoe, Witches 5


Death Busters

Gender: Female
Species: Daimon Humanoid
First Appearance
Manga: Act 27 Infinity 1 Premonition

Viluy is the third of the Witches 5 to confront the Sailor Senshi. She is a level 202 witch and the third strongest member of the Witches 5. Like the other members, she is capable of transforming into a Daimon, though her Daimon appearance was never shown. As Yui Bidou, she was the leader of the Science class at Mugen Academy.

Nomenclature & Etymology


Viluy's name comes from the word "viluite", which is one of the names for the silicate mineral wiluite.

The kanji in Viluy's alias surname translates to "beauty" (美) and either "temple", "shrine" or "hall" (堂). Her given name, Yui (ゆい), is written in hiragana, and thus, can have multiple meanings such as "only", "reason", "tie/knot" or "think".

Viluy might be based on Vili, another of the Norse gods; he was one of Odin’s brothers and was responsible for giving a reason to the newly created humans. This would fit with Viluy’s scientific orientation, and the Norse root might help explain the snowflake motif in her costume.

Old Norse Vili means "will". Old Norse refers to a type of Germanic shrine; a .


Viluy has shoulder-length white hair and blue eyes. She has light blue stockings, blue and black mosaic leotard, blue hat, blue wristband, black star necklace, and blue star earrings.


In Act 30, she targeted Ami during her visit to Mugen Academy. She showed Ami around the school and showed her a miniature version of the Tau Nebula. Viluy set up the computers in the school to extract Hoste from the victims and when she caught Ami, Haruka, and Michiru, she tried to do the same to them as well, but they were able to escape. After Ami transformed into Sailor Mercury she immediately used Mercury Aqua Mirage on Yui, but to no avail. Viluy then revealed her true self and used Mosiac Buster on her, which sent nanobots into Sailor Mercury's body. Soon after, Viluy was killed after Sailor Uranus attacked her with her Space Sword, cutting the Witch in half, and stopped the nanobots from killing Sailor Mercury.

She is revived along with the other Witches 5 by Kaolinite and captures Sailor Mercury. She is permanently destroyed by Sailor Neptune and Sailor Pluto.






  • Viluy is the Witches 5 counterpart to Sailor Mercury.
  • In the Nakayoshi character poll for the Infinity arc, Viluy and her alias, Yui Bidou, were listed as separate choices. She ranked the following:
    • Viluy: Place 40
    • Yui Bidou: Place 37

Death Busters
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