|Alignment:||Black Moon Clan|
|Lives:||Nemesis, later Tokyo (anime only; after being purified by the Silver Crystal)|
|Occupation:||Member of the Spectre Sisters|
|Family:||Koan, Petz, Calaveras (sisters)|
|First Anime Appearance:||An Angel? A Devil? Mysterious Girl From the Sky|
|First Manga Appearance:||Act 16 Yuukai SAILORMERCURY|
|First PGSM Appearance:||N/A|
|English Name:||Bertie (dub, Mixx manga), Berthier (Kodansha manga)|
|Actors:||Yuri Amano (anime); Rumi Kasahara (Crystal); Kathy Laskey (DiC dub), Katherine Trowell (dub 79); Cindy Robinson (Viz dub)|
Berthier was a member of the Black Moon Clan and the second youngest of the four Spectre Sisters. She accompanied Rubeus and her sisters to 20th-century Earth in order to locate Chibiusa and find the Silver Crystal.
In the anime, Berthier was the quiet one of the four Spectre Sisters. She did not often rely on her physical strength, and usually used her Droids to perform her work as opposed to getting personally involved like the other three did. Because Berthier's nature was to avoid combat, she ended up being the last sister to actually meet the Sailor Senshi despite playing a leading role in two of the episodes between her first appearance and their first conflict. This tended to lead the other sisters to think that Berthier was not very strong in general and that she was even incompetent. Despite slight shunning from her sisters, Berthier was always respectful of them, especially with Calaveras and even more with the eldest, Petz. She was shown to tease the younger Koan on different occasions.
Despite her dislike for fighting Berthier was implied to be very intelligent, and when she used her power, she was capable of brainwashing someone simply by looking at them and speaking to them, whereas the other three must relied solely on Droids and devices infused with black energy. She could also use a freezing power to trap her victims in ice with little effort.
Berthier targeted a total of three Crystal Points: Otafukuya, Bob-Floy, and the Chess Tower, which was more than her other sisters. The first two she attacked with help of the Droids Atsugessho and Nipasu; in both cases where she enlisted a Droid, Berthier took over the shop with Dark Power and made regular checkups, rather than staying at the location like her sisters. After her first failure, Berthier was scolded by Rubeus and ordered not to fail again; subsequently, contrasting her usual playful nature, she made dark threats to Nipasu to not fail.
Despite her usual composed demeanor and her own misgivings about how her sisters regarded her, Berthier was nevertheless loyal to them and was distraught when Koan turned to Sailor Moon's side. Being closer to Koan than the others, Berthier was suspected by the others of wavering, and in an attempt to prove her loyalty to the cause, Berthier went after the Crystal Point of the Chess Tower in episode 71, where she learned the identity of Sailor Mercury. Challenging the Sailor Senshi to a handicap chess match in her favor, Berthier nevertheless lost when Tuxedo Mask interfered, and she was then abandoned by Calaveras and Petz.
The humiliation and betrayal drove Berthier to try to kill herself and the Senshi, but Koan's love for her older sister ultimately allowed Berthier to see another chance for herself. She was subsequently healed by Sailor Moon.
Berthier was later kidnapped by her two elder sisters as bait for the Sailor Senshi, but due to her and Koan's will for peace both of her other sisters ended up being healed by Sailor Moon's Moon Crystal Power. After these events Berthier and her sisters moved into an apartment together and ran their own makeup stall, from which Berthier would use the wares and be scolded by her sisters.
- Dark Water - a stream of freezing water which surrounded her and was then blasted towards an enemy, in a similar fashion as Sailor Mercury's Shine Aqua Illusion attack.
- Dark Water Full Power - an advanced form of Dark Water, used in a suicidal fit of desperation. It had the effect of freezing most of the surrounding area.
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 thus challenged 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. The water current - with Mercury in it - was then taken by Rubeus to Nemesis.
Berthier's only appearance in the musicals was in Tanjou! Ankoku no Princess Black Lady (Kaiteiban) - Wakusei Nemesis no Nazo, and she was played by Manami Wakayama. She was very similar to her manga counterpart, and introduced herself as a dowser.
She was shown to be stronger than Sailor Mercury, whom she declared as a rival, but weaker than both Sailor Venus and her older sister Calaveras, which seemed to place her as the second strongest of the Spectre Sisters. She was eventually killed along with her sister Petz by Sailor Neptune's Deep Submerge.
- Dark Water
- Berthier is named for the mineral berthierite, an iron sulfide.