Two Siblings In One

"Hey, Rubedo! Be sure to breathe deep and inhale the particles that composed me!"

— Albedo, Xenosaga II

This occurs when a character's sibling dies and the character absorbs their soul, or the dead may force their Life Energy on to their sibling. The rule of "two souls cannot control a body at the same time" usually applies and the siblings will switch control over the body. The original owner of the body is usually in charge, but the dead sibling will take control at key moments. Usually accompanied by friends of the 2-souled-twin saying they are Not Himself. In most cases, when the inhabiting sibling is in control, a distinct feature will let the audience know. This can range from Mind-Control Eyes, to a colored aura that appears around the character; in some cases, the voice will also change.

Compare Body and Host, Jekyll & Hyde and Sharing a Body. Literal version of My Sibling Will Live Through Me.

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Examples

Anime & Manga

• In Basilisk, the Big Bad of the group apparently absorbed his twin brother. His brother is still alive, so to speak, as a monstrous symbiote who gives his brother immense regeneration in return for surviving freakishly. This also counts as squick, since said symbiote is only able to speak through his brother's ripped throat.
• Invoked by Hansel and Gretel in Black Lagoon. They're siblings, but who's the boy and who's the girl? Good question. They change around at will — and when one of 'em winds up dead, the survivor happily declares that they're still together, even as she changed into a he... (Note that all we see is a change of wig and voice — but it is implied that whatever physiological difference there may have been between them, is no longer visible without an autopsy.)
• Yusa from Charlotte unknowingly has the ability to channel the souls of the dead, which her recently deceased older sister Misa uses to possess and protect her. Yusa doesn't learn the truth until after Misa has Yuu take both of their powers, feeling that it's time for her to finally move on.
• In Le Chevalier d'Eon, Lia forces her soul on to D'Eon so that she can take revenge on her murderers.
• In Chobits, Freya inhabits her sister Chi's body, sometimes taking control, but otherwise only observes and occasionally makes contact.
• In Darker than Black Hei's Contractor Power comes from his sister, who joined with him during the Heavens Gate Incident.
• This originally was the main plot of D.Gray-Man. In the pilot chapter Zone, Allen makes a deal with the Earl of Millennium in order to resurrect his dead sister Robin. But this was actually a trick, and it is revealed later that Allen's soul was taken by the Earl and that it is actually Robin living through Allen's body. Of course, this was changed a lot in the actual manga/anime and Allen doesn't even have a sister in D.Gray-Man.
• Fullmetal Alchemist: The "Slicer brothers" of the Fifth Laboratory, who are actually the disembodied souls of two serial killer brothers bound to a suit of armor.
• In the second OVA of Fushigi Yuugi, Suboshi is revealed to be alive and inhabiting his twin’s body.
  • The brothers share a psychic link that allows them to sense the other’s life force and communicate by writing messages on their hands. Even when Amiboshi lost all memories of his past life, he could still feel Suboshi’s death.
• Hanako and the Terror of Allegory: Dead sibling Nozomi takes over Kaede's body as part of a revenge scheme.
• Something similar to this happens in the anime ending of MÄR, only it's between a clone and the original, not siblings. Also they each had half of the original soul, instead of two souls. After she dies, Snow merges back into Koyuki so she can live on as one person to be with Ginta.
• Conjoined twins Sakon and Ukon from Naruto. Well, not so much conjoined as having the ability to meld on a cellular level with other humans, so one is constantly "riding" the other.
• In Persona -trinity soul-, the main character's brother had a twin sister that died when she was young. Her brain was transplanted into his. While he remains in control for the duration of the show, at the end of one episode, he turns into her.
• Psychic Academy had a pair like this, where the sister has her brother's heart. Comes as a surprise, because in the early part of the story it is the brother that is dominant (and The Antagonist).
• In RDG: Red Data Girl (based on a novel series), the Shouda triplets are a variant: Masumi died of a heart condition when he was six, but his remaining siblings, Mayura and Manatsu, can summon his spirit or even have him take one of their forms and impersonate them when they're off doing something else.
• SHUFFLE!:
  • Sia absorbed her twin sister Kikyou's soul.
  • Nerine has a similar thing with Lycoris, although in this case it's "clone" rather than "sibling".
• This is the setup with Yayoi and Uzuki in Softenni. It helps that Yayoi comes from a family of spiritualists.

Comic Books

• One of the big twists in Avengers Arena is that the character of Apex has her own twin brother inhabiting her body. They're a set of twins that shared the same body until Apex took over.
• The Bronze Age Marvel Comics character 3-D Man was the soul(?) of a dead brother, brought back to life by the live brother when concentrating through his glasses.
• From Marvel Comics, Brother Voodoo with Jericho (living) and Daniel (spirit) Drumm. Daniel could leave Jericho's body to possess other beings.
• Doctor Occult and his companion Rose Mystic of DC Comics are this, unless they aren't. They either tell different false versions of their origin, or all the versions are true in some sense; with mystic characters it's hard to tell. In some versions of their backstory, Doctor Occult absorbs her soul when she's dying, and they share the body, switching forms based on which one is in the figurative driver's seat. Whether she's his fraternal twin sister, lover, partner, fellow graduate of a mystic academy, and/or some combination of these varies with the retelling. In other versions, they're the male and female aspects of the same being (and in some versions, they started out as the first, and eventually blended so thoroughly they became the second). If DC had a mystic Facebook, their relationship status would definitely be "Complicated."
• Firestorm from DC Comics was this, before Doing In the Wizard and becoming a fire elemental.
• This was the origin of The Golden Age DC Comics superhero Captain Triumph. When Lance Gallant swore revenge for his brother Michael's death, Michael's ghost appeared to him, and by merging they gained superpowers.
  • And in JSA: The Golden Age, it's what continues to haunt Lance as he desires to have a normal life after the war.
• Haunt is about a Badass Preacher haunted by his brother, a deceased secret agent, becoming a superhero.
• Karma of the New Mutants absorbed her fraternal twin brother, symbolized by his half of the yin-yang symbol appearing on her outfit.
• In one of the last issues of Paperinik New Adventures, One absorbed the last data of Two (who was about to be deleted). However, since there was so little of him left, One is always in control, and manages to become Odin Eidolon.
• The French comic La Rose Ecarlate has the twist that Polar Opposite Twins Artemis and Apollo actually share Artemis's body unbeknownst to her, which in turn means that she is prone to feeling disoriented and confused once she comes back to herself.

Fan Works

• Children of Elm Street: A Nightmare Tale: As revealed in the third interlude, Shelby contains the soul of her deceased twin sister Tory, who was killed by Freddy when the two were six. While Tory's soul was initially absorbed by Freddy, when he attacked Shelby several years later, she fought back and entered Shelby's body, driving him off; ever since, the two have shared Shelby's body. While Shelby retains control most of the time, Tory takes control while they sleep.
• Dual Destinies: Ranma is an only child, but then learned from Soren and Taron, two immortal twin fighters, that he actually has the souls of twins in his body, meaning he was supposed to be born as a pair of twins. However, due to interference from the Dark World, one of them was destroyed during Nodoka's pregnancy, so Soren and Taron managed to save the soul and fuse it into the other body. They then split Ranma into twins, Ranma Red and Ranma Blue, to train them to become the final saviors of the Multiverse.
• A variation in The Mountain and the Wolf: Gregor Clegane was killed twice by the Wolf, first as himself and the second time as a zombie. Both versions are resurrected in a single monstrous body by the Chaos gods.

Films — Live Action

• The big twist of Malignant is that Madison's murderous twin brother Gabriel doesn't just exist "inside her head", he literally is inside her head.
• In Wonder Man 1945, Edwin Dingle's late twin brother Buzzy Bellew possesses him as "encouragement" to help put the perpetrators of Buzzy's murder behind bars.

Literature

• Angela and Diabola: This is how the Surprisingly Happy Ending comes about. When Evil Twin Diabola dies, good twin Angela absorbs her evil and becomes an ordinary, basically good yet flawed person. The change is signified by one of Angela's blue eyes turning green, like Diabola's were. This is justified by the fact that apparently, Angela and Diabola were always meant to be just one person, but that some "cosmic accident" caused them to be born as a good twin and an evil twin instead.
• The Young Adult novel Dangerous Boy uses this as an update on The Strange Case of Dr. Jekyll and Mr. Hyde, having Logan and Daemon be twins, one of whom died before the story started. Their switch is triggered by lightning.
• Thad Beaumont/George Stark from Stephen King's The Dark Half. An odd example in that it starts with Thad putting his alter ego to rest. But then Stark gets a body of his own...
• In the Disgaea Novels the twins Shas and Kira came to share Shas' body when Kira died shortly after being born.
• In Distant Waves, the twin sisters Amelie and Emma seem to share Twin Telepathy. Near the end of the book when Emma dies of hypothermia, her soul goes into Amalie's body.
• The plot of Haunted Sister by Lael Littke. Janine's twin Lenore died when they were young. After a near-death experience where Janine goes to heaven but is told it's not her time, Lenore's soul comes back with her. The two don't get along very well, and Lenore increasingly tries to take over more.
• In the Ixia and Sitia series, this happens to the Commander with his mother — she dies giving birth to him and her soul goes into his body, also changing his biological gender down below. The Commander usually is in charge of the body, but his mother acts as the Ixian ambassador when they are away from home.
• In The Locked Tomb series, a necromancer attains Lyctorhood (which grants immortality and extreme power) by killing their cavalier (a sort of personal bodyguard) and consuming their soul. This isn't usually a sibling bond, but there are a few instances in the series in which the specific trope is invoked. In Gideon the Ninth, Coronabeth (who isn't actually a necromancer but is posing as one) is devastated when her twin sister Ianthe becomes a Lyctor by consuming their cavalier's soul instead of hers. In the sequel, Harrow the Ninth, we learn that Augustine the First did this to his brother Alfred, who served as his cavalier (it doesn't explicitly say they were twins, but it doesn't say they weren't, and since he becomes something of a mentor/foil to Ianthe, it may be implied).
• Played with in My Next Life as a Villainess: All Routes Lead to Doom!. The character that everyone refers to as Sirius Deek is actually his illegitimate half-brother Rafael Walt. Sirius' mother coerced a man into performing a dark magic ritual and transferring Sirius' consciousness into Rafael's body. Rafael did end up inheriting all of Sirius' memories, though he still effectively remained himself, and he's been pretending to be Sirius for years to avoid being killed.
• In Simon R. Green's Secret Histories, members of the Drood family always give birth to identical twins, thanks to a Deal With... Something their ancestors made a long time ago. This surprises the main character, who can't recall any of his family members being twins... because they're bonded to their siblings at birth. Those gold torcs they wear are actually made of their souls.
• The Discworld novel Thief of Time has an interesting variant of this. Siblings Jeremy Clockson and Lobsang Ludd are not so much identical twins, as the same baby born twice owing to a literal hiccup in the flow of Time. They then receive foster upbringings and educations in circumstances and environments as completely opposite as it is possible to have — although both are intimately to do with Time. At the denouement of the story, the time glitch that created them is resolved and the two merge for the first time — although Jeremy's essence lives on as a secondary part of Lobsang.
• In The Thirteenth Tale, Vida Winter is a bit ambiguous about her identity after losing her sister.

Live-Action TV

• In Heroes, Niki Sanders manifests the consciousness of her dead, older sister, Jessica Sanders, and gains Super-Strength when she does so. Jessica died protecting her sister from their abusive father and continues to protect her, even if she uses violent and sociopathic means to do so. It was originally not clear whether this was actually two minds in the same body (though "Jessica" seems to think so) or just a regular old Split Personality. It seems to be "normal" crazy, considering that Niki was eventually able to use the powers "herself", and that she eventually manifested other personalities.
• Cary and Kerry Loudermilk in Legion (2017) are mutant siblings who share a body. Cary is a nerdy white guy, Kerry is a Native American woman, and they were born to Native parents. So when Cary was born their father accused their mother of cheating on him. Kerry didn't even first appear until Cary was several years old. The pair shares a degree of Synchronization, and if Kerry is wounded, Cary can heal her by rejoining, with him taking on her wounds instead.
• A variant occurs in Once Upon a Time, with Rumpelstiltskin absorbing his son, Baelfire/Neil, after Neil unknowingly used his own life force to fuel a spell to bring his father back from the dead.
• The Outer Limits (1995): The episode "Inner Child" explores this when a woman is attacked, wakes up in the hospital, and finds out that she had a twin that died and was absorbed into her body. The twin starts taking over (with the eye color changing to indicate who is in charge), but it's revealed she's not doing it to be malicious; the living twin simply can't remain dominant any longer. However, both twins are still alive by the end of the episode, though the dominant/recessive roles have switched.
• A father/daughter example in the Star Trek: The Next Generation episode "The Offspring". When Lal's positronic brain fails, Data incorporates her memories and subroutines into his own.
• In the Season 2 finale of Titans (2018), Jericho Wilson uses his powers to jump from his father's body to his sister Rose's. Unlike Slade, she's a Willing Channeler and they wind up as a Brother–Sister Team in one body.

Tabletop Games

• Grim Hollow: Enforced by the Laneshi, the setting's merfolk equivalent. When a pair of twins are born, tradition decrees that the younger twin is sacrificed through a necromantic rite that binds them to the older twin as a spirit guide.
• Warhammer has Vilitch the Curseling, who began life as a feeble and oppressed shaman's apprentice forever in the shadow of his brother Thomin. Vilitch's bitter prayers were answered by his patron god Tzeentch when he was magically fused to the shoulder of his hulking warrior-twin and able to take control of their conjoined body. Thomin is now a near-mindless thrall... at least until the End Times, when Tzeentch reverses the curse, with Thomin in charge and Vilitch the slave.

Video Games

• In Beyond: Two Souls, the ending reveals that Aiden, the entity that's been with Jodie and protected her for her entire life is the soul of her stillborn twin.
• A major gimmick in Clock Tower II: The Struggle Within is exactly this. In the backstory, Alyssa's twin brother Bates ended up being killed early in life, only for his soul to end up inhabiting her body, leading to him manifesting as a Split Personality for Alyssa, a rather vengeful one as well. Swapping between Alyssa and Bates having control is a major part of the game, and many events will change based on who's currently fronting, often to Guide Dang It! degrees.
• Danganronpa V3: Killing Harmony: Korekiyo Shinguji's Split Personality is that of his dead sister, whom he was... very attached to. He claims it's her ghost possessing him.
• .hack//G.U. has an implied example similar to the Danganronpa V3 example above. The "Saku" half of Sakubo is a Split Personality of Iori Nakanishi (who plays the "Bo" half) based on his stillborn older sister Sakura, complete with Split-Personality Makeover depending on who's fronting. Given it's .hack, it would not be too much of a surprise if this trope really was in play, but it's never made explicit.
• In Inazuma Eleven 2, after Fubuki Atsuya dies in an avalanche, his brother Shirou develops Multiple Personality Disorder, with the second personality being Atsuya's. This is played as Dual Mode Unit in the game while in the anime adaptaion, the drama is expanded into Split-Personality Takeover.
• Pathfinder: Kingmaker gives this an unusual twist with Kaessi — she's actually twin Tieflings — Kalikke and Kanerah — with opposing personalities that have to swap places in order to exist on Golarion. The one not there is effectively left in stasis in a Pocket Dimension until her sister can swap. An item discovered as part of her questline allows her to control this, rather than have it occur at random.
• In Sa Ga Frontier, Blue's quest involves gathering magical knowledge and killing his brother, Rouge in a Duel to the Death, to attain his true strength. Obvious spoilers are obvious, given the trope we're dealing on. In game, there are several opposing types of magic (such as light/dark and time/space, and the player can only obtain one of each set. Whatever Blue doesn't obtain, Rouge does. The winner of the battle to the death absorbs the loser's power and thus obtains every magic in the game.
• In Undertale's backstory, Chara sacrificed their life,and their adoptive brother and prince of the Underground, Asriel, absorbed their SOUL and went to the surface to fulfill Chara's last wish: to see the Golden Flowers from their village. However, Asriel died because of a misunderstanding on the humans' part.
• Vermintide II: Implied regarding Sienna's Necromancer career. The career DLC was released soon after a mission where the heroes defeat Sienna's Evil Twin Sofia, a Necromancer, and Sienna's abrupt change in magical practice coincides with other unusual behavior, leaving the other heroes worried that there's "more than one set of hands on the reins".
  Markus: You hear funny things about twins, don't ya? And necromancers. And we did just kill her necromancer twin.

Visual Novels

• In the original Ace Attorney trilogy, Mia Fey is killed at the start of the second case. For the rest of it, she's seen through her sister, Maya Fey, being a Willing Channeler and calling upon her ghost.
• This trope forms a core plot point with Hajun from Kajiri Kamui Kagura. Unbeknownst to even himself, he had a twin brother/sister that was fused to him in the womb becoming known as the Tumor. The Tumor is the source of the constant presence Hajun feels that just won't leave him alone as well as the source of his constantly rising power. Additionally, said brother/sister also constantly leeches power from their brother and feeds it to Habaki and his crew. In the end the Tumor is removed from Hajun allowing Habiki to defeat him allowing for the Tumor to become the next God of the Throne.

Webcomics

• In Kid Radd, Sheena's "sister" (a version of herself from Kid Radd 2) is destroyed, but lives on through Sheena absorbing her code.

Web Videos

• Played literally with BobbySue from the Disrespectoids web show based off the commercials. The two twins stepped on the pouch at the same time (as seen in the opening) and they became stuck together.
• hololive has Akai Haato's two personas, Akaihaato and Haachama. Originally just a case of Same Character, But Different and Self-Applied Nickname, with Haato going from a Tsundere to a Cloud Cuckoolander calling herself Haachama, to celebrate reaching 1 million subs, she dropped her strange personality and started going by Akaihaato again, and then started a story arc establishing Akaihaato (now a soft-spoken Nice Girl instead of a tsundere) and Haachama as being two sisters fighting for control of Akaihaato's body, which they've been sharing since Haachama died in a traffic accident. In the end, the two reconcile, and Haachama is brought back to life with her own body, somehow. Or maybe it was All a Dream, Haachama never died, and they never actually shared a body. The ending isn't exactly clear on how it happened, just that they are both alive and in seperate bodies.

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