When Marinette wonders if love between a Ladybug and Black Cat holder can work out, Tikki shows her how to communicate with a past holder of her Miraculous: Jeanne d'Arc. Meanwhile, Jalil's anger about his sister's absence results in him becoming re-akumatized into the Pharaoh.
Tropes:
- Anger Born of Worry: Jalil clearly misses his sister and fears she was manipulated to leave present-time Paris to the extent that he is intentionally angry enough to akumatized to get her back. He doesn't get to be reunited with her, but clearly accepts the situation being of her own decision after his Book of Truth proves it to him, leading him to renounce the Megakuma within him.
- Anti-Villain: Jalil is far from the first person to be willingly akumatized but he's the first one to do it for altruistic reasons.
- Breaking Old Trends: The first Season 5 episode title that doesn't tie directly to a Kwami whose power is exploited by Monarch.
- The Bus Came Back: Alix returns as herself and as Bunnyx (though entirely unspeaking) to find a note Ladybug left her in the museum so that Bunnyx could know to check the weather in Paris in the future to leave Ladybug the answer to the Book of Truth's question while still keeping to her self-imposed exile from present times to secure the Rabbit Miraculous.
- Call-Back:
- Tikki's Kwagatama, gifted to Marinette a while back, factors into the plot here, enabling her to communicate with past holders. Alix is shown to have one of her own, and Plagg spits one out for Adrien at the end of the episode.
- To contact past Miraculous holders you need a special sigil hidden on various works of art depicting one of the said holders. Their existence was established back in episode "Feast".
- Jeanne d'Arc already appeared momentarily in "Ephemeral".
- Cat Noir mispronounces an unfamiliar word as "hakunamatata" like he did in "Oblivio".
- Conspiracy Theorist: There's a number of these on the internet that believe that Ladybug and Cat Noir aren't as benevolent as they seem. Jalil initially believes them out of anger about his sister leaving for Miraculous-related reasons.
- Dark Is Not Evil: Dark Grimalkin wielded the Black Cat Miraculous and served a rival king, but he and Jeanne are both good people and he balks at harming innocent civilians.
- Does This Remind You of Anything?: Jalil accepting conspiracy rallying social media posts like ones made by Chloé Bourgeois despite public knowledge saying otherwise is similar to how many conservatives accept similar posts in recent years.
- Double-Meaning Title: The power to call forth memories of past holders is called "Reunion", and Jalil desires a reunion with his sister.
- Draco in Leather Pants: In-Universe; one commenter on the internet believes that Monarch wants to use the wish granted by the Ladybug and Cat Miraculouses for a benevolent goal like world peace. Needless to say, given the numerous acts of terrorism he's committed by this point, that characterization is a bit of a stretch.
- Faking the Dead: Jeanne didn't actually die at the pyre. She made it look like she did, then she and Grimalkin renounced their Miraculouses so they could live a normal life together.
- Foreshadowing: Tikki comments that while there were past Miraculous holders in love they didn't have to deal with an evil Monarch going after them. Turns out she's half right: while no THE Monarch wanting their Miraclouses, Scarlet Fate and Dark Grimalkin were still hunted by their kings for refusing to fight each other. This forced them to relinquish their Miraculouses so they can live in peace.
- Friend to All Children: During one of their battles, Scarlet Fate and Dark Grimalkin teamed up to protect a group of children caught in the crossfire.
- Happily Ever After: Marinette asks if this happened after Jeanne faked her death and gave up her Miraculous. However, the apparition doesn't actually know, so it is left ambiguous.
- Hero with Bad Publicity: Apparently there are online forums that have started bashing Ladybug and Cat Noir for not stopping Monarch while also framing the purple menace in a positive light. To no one's surprise, Chloe is an ongoing member.
- Historical Gender Flip: Bunnyx found that Aramis, one of the three musketeers, was actually a woman, and left a note to Alim complete with a photograph of Aramis to prove it.
- Hoist by His Own Petard:
- The Book of Truth asks trick questions meant to capture the heroes, but also lets them pass for getting the questions right, leading them directly to Pharaoh.
- The very powers Monarch granted to Pharaoh reveal that Monarch was manipulating him, allowing Jalil to reject the akuma.
- Impossible Task: Played with. One of the questions asked by the Book of Truth is the weather conditions on the same day 200 years in the future. While this would obviously be impossible for the layman, Pharaoh knows that Ladybug has a means of getting the answer: Bunnyx. The idea is that he'll have to summon her back to the present to do it, though Ladybug gets around that.
- Internal Reveal: Both Alya and Cat Noir learn of the existence of the Kwagatamas.
- Invisible to Normals: Only the current holder of the Miraculous can see the apparitions of past holders. When Marinette first starts seeing and talking to Jeanne, Alya thinks she's gone crazy. Jeanne tells Marinette to get used to people thinking that.
- Irony: Jeanne is skeptical about Ladybug's crush seeing how "puny" Cat Noir is, to which she responds by pointing out his qualities such as his sensitivity and devotion. Ironically, Jeanne fell in love with Dark Grimalkin because of his kindness and compassion.
- Karma Houdini: Nobody ever finds out that Jalil called for Monarch to Akumatize him, so he doesn't get punished for it.
- Living Memory: A Kwagatama can summon apparitions of past Miraculous holders. Only the current Miraculous holder and their Kwami can see and hear them. These apparitions are created from the memories of the individuals while they were holders, and thus they can't remember anything that happened to them after they renounced their Miraculous.
- Love Across Battlelines: Jeanne fell in love with Dark Grimalkin, an English knight and holder of the Black Cat Miraculous. However, they both realized that their true enemies were not each other, but rather the kings causing the war.
- Magic Knight: Both Jeanne d'Arc (AKA Scarlet Fate) and Dark Grimalkin. They utilized the magical powers of the Miraculouses and dressed in medieval armor, as well as used weapons not provided by the Miraculouses, a sword and battle axe respectively.
- Neurodiversity Is Supernatural: It's revealed here that the "voices" Jeanne d'Arc heard in life were actually her talking to her predecessors through her Kwagatama.
- Not Brainwashed: Jalil is convinced by the internet that Alix didn't leave willingly and Ladybug is actually a bad person, resulting in him calling out for Monarch to akumatize him.
- The Omniscient: The Book of Truth apparently knows everything, from historical facts, to personal feelings and motivations, to the Parisian weather 200 years in the future.
- Self-Disposing Villain: Ladybug ultimately defeats Pharaoh by challenging him to use his own powers, which confirms the truth, to determine who's deceiving him: the heroes or Monarch. Naturally, he's set right and rejects Monarch's megakuma.
- Shout-Out: Cat Noir mispronounces kwagatama as "hakunamatata".
- Social Media Is Bad: Jalil falls into online conspiracy theories out of concern for his sister, believing Ladybug must have brainwashed her somehow. The fact that his father Alim was there does not dissuade him.
- Superheroes Stay Single: After hearing Jeanne's story, Marinette worries this might be the case. She considers that she'll have to give up her Miraculous in order to have a shot at love.
- Sudden Lack of Signal: Inside of Pharaoh's pyramid, not even Ladybug's bugphone has a signal.
- Sure, Let's Go with That: Ladybug explains how she used her kwagatama to summon the Living Memory of Jeanne d'Arc, one of the past holders of the Ladybug Miraculous. Cat Noir is very impressed that she had the foresight to summon a historical figure to help them fight a villain who quizzes them on history trivia. Ladybug awkwardly laughs and agrees with him, too embarrassed to explain why she actually summoned Jeanne (because she's looking for Jeanne to give her hope that two Miraculous holders can be in a romance while "on the job"...because she's into Cat Noir).
- Unexpectedly Obscure Answer: The Book of Truth poses questions that at a glance seem simple, but actually rely on obscure knowledge to get the right answer; for example, knowing that a white horse is actually faded gray, or just how complicated France's political situation was in 1423.
- The Unmasking: Dark Grimalkin removes his helm in front of Jeanne and the children caught in the crossfire of their battle, revealing his kind and compassionate face.
- What Does She See in Him?: This is Jeanne's initial reaction to seeing how (in her words) puny Cat Noir is.
- Wouldn't Hurt a Child: Despite being willing to fight for his kingdom, Dark Grimalkin refused to hurt the children of the enemy kingdom.
- Write Back to the Future: Alix hides messages in paintings for her father, left there hundreds of years in advance. Ladybug then exploits this to get Alix to leave her the answer to a question about the future.
- Ye Olde Butcherede Englishe: In the English translation, Jeanne throws "-eths" on completely random words.
