“Berthier, using people and deceiving them is no way to live your life. Truly helping, loving and caring for other people without expecting something in return, that's the way to fill one's life with meaning. Humans are born with the power to love and care for each. That's what you need to understand.”
— Usagi Tsukino
(DiC Episode: "Checkmate")
Berthier sets out to prove her worth to her master and sisters by contaminating a Chess Tower which would one day become a Crystal Point. Though her values are questioned after a confrontation with Sailor Mercury along with Koan.
Tropes in this episode include:
- Badass in Distress: Berthier successfully traps the Guardians in a freezing ice bubble while her and Mercury duke it out with chess.
- Character Development: The old man who created the Chess Tower notes how Ami looks more happy and at peace compared to her past self who played to hide her loneliness. Ami credits having made wonderful friends who helped with her development.
- Chekhov's Gunman: Koan is shown being watched by her former comrades as she enjoys living like a normal cosmetics lady and later appears alongside the girls as they root for Ami to win. She would be instrumental in convincing Berthier to renounce her wicked ways.
- Chronic Backstabbing Disorder: Rubeus reveals to the audience that he thinks of the Sisters as nothing more but pawns for him to exploit and discard as soon as he's done with them.
- Despair Event Horizon: Berthier admits she knew that Petz and Calaveras would abandon her should things go wrong, but she had hoped she'd be wrong. She wasn't, and it causes her to snap.
- Don't You Dare Pity Me!: Berthier's Stepford Smiler facade only cracks when she sees Ami and the others expressing sympathy rather than mocking her for being betrayed by her sisters.Berthier: Go on, laugh. Even I think it's funny that I was counting on my sisters to help me. The joke's on... me. [beat] I SAID LAUGH!
- Evil Cannot Comprehend Good: Rubeus and the remaining Spectre Sisters spy on Koan as she lives like an ordinary woman and can't understand, nor care, why she would want to live that way.
- Evolving Credits: This episode showcases a new opening that features more members of the Black Moon Clan, Chibi-usa, a mysterious Sailor Guardian in black, and the queen and king of Crystal Tokyo.
- Faux Affably Evil: While maintaining a polite and elegant manner, Berthier insults Usagi and Makoto for their beliefs on playing for fun while asserting that they'll never get anywhere with that shallow thinking.
- Fixing the Game: During her final round against Sailor Mercury, Berthier uses special pieces that freeze the entire room while also taking away several of Mercury's pieces.
- Foreshadowing: Berthier is the only one of the three Spectre Sisters to be sad and curious about Koan's departure, albeit trying to hide that from the others. This inner conflict makes her sloppy and acting harsher to try to overcompensate, as well as receptive to Koan's attempt to reach out to her.
- Happily Failed Suicide: Just like Koan, Berthier lives a much enriching life after she's talked out of her suicide attack.
- Heel–Face Turn: Berthier is convinced to embrace humanity and allows Sailor Moon to purify her so she can live like a normal human woman.
- Human Popsicle: During the death rematch, Berthier informs Mercury that losing their chess pieces while playing will cause her to be frozen solid. This ends up happening to the Berthier during her Villainous Breakdown.
- Hypnotic Eyes: Berthier uses her special eyes to manipulate the tower's receptionist.
- Instantly Proven Wrong: Usagi informs Chibi-usa that she isn't going to hold back against beating the little girl at chess. It then cuts to Chibi-usa declaring checkmate on Usagi.
- Internal Reveal: Berthier learns that Ami is Sailor Mercury.
- Interrupted Suicide: After the Sailor Guardians and Tuxedo Mask thwart her plans, a suicidal Berthier tries using her Dark Water technique to drag the Guardians with her. Fortunately for Berthier, Koan talks her out of it.
- Ironic Echo: Berthier "assures" her older sisters that she'd never think of asking for their help during her mission. But after Tuxedo Mask interferes with her game while freeing the imprisoned Guardians, she instantly turns to her older sisters for help.
- Locked Out of the Loop: The remaining Spectre Sisters have no clue as to why Koan decided to leave their organization to become a normal woman.
- Losing Is Worse Than Death: Berthier boasts to Ami and her friends that winning is the most important part of any game and that playing without wanting to win is a waste of time.
- No-Sell: Mars tries to use Burning Mandala on their bubble prison but the frozen surface causes the rings to ricochet without making a scratch.
- No Sympathy: After Berthier returns from her first failed attempt, Petz and Calaveras condescendingly ask if she still made an effort to complete the contamination process. They even remind her that they don't need another disappointment like Koan.
- Oh, Crap!: Koan reacts this way when she sees that her older sister is competing in the chess tournament.
- The Power of Love: Koan uses the power of familial love to help Berthier overcome her despair and assure her that she can still be loved and appreciated.
- Reformed, but Not Tamed: Played for Laughs. Berthier is now one of the good guys but she still resorts to cheating in order to win at chess.
- Rewarded as a Traitor Deserves: Rubeus plans to properly punish Koan for betraying the Black Moon Clan.
- Shadow Archetype: Continuing the trend, Berthier is what Ami could have become if she prioritized winning and being the best in life over accepting that there's more to life then winning. Additionally, Berthier developed this mindset because she's in the company of people who only care about her successes while Ami's values were formed thanks to the support of true friends who promise to stick by her for her victories and failures.
- Smart People Play Chess: Resident genius Ami is a wiz at playing chess and is preparing to participate in an upcoming tournament. Berthier herself is participating but uses underhanded tactics to win.Ami: Chess is the perfect mental game for developing a calm demeanor and promotes the ability to make precise decisions.
- Soft-Spoken Sadist: Berthier maintains her soft and ladylike mannerisms as she viciously attacks Ami with her Dark Power.
- Stepford Smiler: After being abandoned by her other sisters, Berthier starts crying, only to force a smile when talking about how not even sisters care about each other and claiming that believing otherwise is funny.
- Taking You with Me: Berthier's final act of villainy involves creating an ice age within the tower that'll kill the Guardians and herself.
- Tears of Joy: Koan cries these as she runs to her sister jubilated in the fact that Berthier stopped her suicide attack.Berthier: Koan, are you crying? Are you hurt?Koan: No! I'm just happy!
- That Woman Is Dead: Petz and Calaveras have cut their little sister Koan from their lives and want nothing to do with her, thanks to her Heel–Face Turn. Calaveras even refers to their group as the "Three Spectre Sisters".
- The Unmasking: Ami has no choice but to transform into Sailor Mercury in order to fight Berthier which leads to her discovering her civilian identity.
- Villain: Exit, Stage Left: After her first attempt to contaminate the Chess Tower is ruined by the arrival of Sailors Jupiter and Moon, Berthier decides to vamoose out of there.
- Villainous Breakdown: Once she's abandoned by Petz and Calaveras, Berthier loses her Affably Evil demeanor she'd shown for most of her appearances by initially assuring the Guardians she was right on how pointless it is to care about other people and then unleashes Dark Water "Full Power" to freeze the tower at the expense of her life. Fortunately for Berthier, Koan intervenes.
- You Are Not Alone: Koan steps up to remind Berthier that she isn't alone and that she is worth loving.
- You Have Failed Me: Petz and Calavaras chew out Berthier for her failures and order her to finish her assignment or die trying.
