Viluy

ビリユイ

Viluy (known as Byruit in the dub) is the fourth member of the Witches 5, named after the mineral viluite.
In the anime, Viluy was assigned the task of gathering pure hearts following Tellu's death. To accomplish this, she programmed all the computers at Infinity Academy to extract the pure heart crystals of their users during a national practice exam. She also possessed the "Mosaic Buster" attack (called "Mosaic Energy Blaster" in the English dub), which released a swarm of nano-robots from her wristband. She initially achieved great success and nearly defeated Sailor Uranus, Sailor Neptune, and Sailor Mercury (against whom she held a personal grudge), until her wristband suddenly malfunctioned due to damage inflicted by Sailor Moon. The nanomachines dissolved their own master, effectively killing her and leaving behind only her bracelet.
In the manga, Viluy was the third witch to appear, preceding Tellu. She was ranked at Level 202 and led the Science Division of Infinity Academy under the alias Yui Bidoh. Her story in the manga is essentially the same as in the anime, except that she meets her end by being cut in half by Sailor Uranus's Space Sword.