Member of the Ayakashi Sisters
Berthier has white hair that is braided into a ponytail and she also has blue eyes. She wears a sky blue leotard and matching thigh-high boots. She is the shortest sister out of all of the Ayakashi Sisters.
Black Moon Arc
Berthier appeared in Act 16 of the manga as the architect of 002: Operation Remove. An expert dowser, her goal was to find Chibiusa and the Sailor Senshi with her dowsing ability, kill them and infiltrate Tokyo with Droids. She was thus challenged by Ami Mizuno to a chess match as a pretext for luring the Senshi to her. She managed to trap Sailor Mercury in a water current before she was killed by Sailor Moon's Moon Princess Halation. The water current - with Mercury in it - was then taken by Rubeus to Nemesis.
Berthier uses Dark Water to make it whirls and streams that can imprison the enemy and strangle him.
Berthier is named for the mineral Berthierite. Bertie's Japanese name is Beruche. Beruche is a shortened for of the mineral, Berucheko (the ko part that was removed is the Kanji for "mineral/ore"). Berucheko is the Japanese name for Berthierite.* Her DIC name Bertie which could sound like Birdy could be in contrast to Koan's dubbed name Catzi, which both names indicate "bird" and "cat".
- She is the Ayakashi Sister equivalent of Sailor Mercury.
- In the Materials Collection, her ideal voice was described as a sugary, lisping voice which her DIC voice portrayed her as surprisingly well.