Reincarnation (trope)

""Each of us plays a role; each time a different role. Maybe the last time I was the interrogator and you were the prisoner. The players change, the story remains the same.""

- Leoben to Kara Thrace in Battlestar Galactica, "Flesh and Bone".

One or more of the main characters is the reincarnation of someone from the past, and they are forced to live with the effects of their previous incarnation's life, loves and choices. A device seen in some Shojo stories, often allowing for a "destined love that survives death" plot element. Also used for a "duty that survives death" plot as well. Sometimes allows for Time Travel to previous incarnations in the form of Visions of Another Self.

Usually, just like an Identical Grandson, a reincarnated person looks exactly like their previous self, unless the contrast is used for some irony—i.e., a pair of lovers being reincarnated as the opposite genders. Roles can change as well for dramatic effect. The Woobie might be reborn as The Hero, a villain finds redemption as a florist, but the bickering Vitriolic Best Buds are still at it!

When it's used in a Western series, the greater religious aspects are often ignored. It's common for the reincarnated character to have some form of Past Life Memories, though Resurrection Sickness may set in with the flood of new thoughts. May manifest only in Dreaming of Times Gone By.

If you're looking for a reincarnation that occurs over the course of a series, see Back from the Dead. If a character explicitly has the power to reincarnate every time they die, it's Born-Again Immortality.

For the 2005 Japanese horror film, see Reincarnation (film).

For the Flash game series about demons recapturing escapees from Hell, see Reincarnation (video game).

Anime and Manga

 * Kagome in Inuyasha. Thanks to Time Travel and a little magic, she co-exists with the person she is a reincarnation of.
 * Tuxedo Mask and all of the earth's senshi aside from Chibi Moon in Sailor Moon. In the manga, Sailor Pluto dies in the future, then reincarnates backwards in time so that her present self can still guard the Time Gate while still helping out.
 * Justified because she was the guardian of the Space-Time Corridor/Gate, a place where Canon already explained that the time doesn't flow, so she could reincarnate in any time period.
 * Setsuna in Angel Sanctuary. The reincarnation may share some similarities with Alexiel but is not exactly alike each also it changes gender randomly.
 * In the manga, it's revealed that.
 * Dragon Ball love this trope: Piccolo being the reincarnation of Piccolo Sr. and Uub being the reincarnation of Kid Buu. Interestingly, both of them are good guys, are reincarnations of Big Bads (of the Complete Monster variety at that) who had epic fights with Son Goku and both had a "rematch" with him in a Tenka'ichi Budokai.
 * Piccolo Jr. took longer to befriend Goku, because he actually remembered his past life; while never as evil as his previous self, Piccolo Jr. was initially quite ruthless and went through a somewhat prolonged Heel Face Turn (fueled by two Enemy Mine arcs in a row, and Goku's son as a Morality Pet) after his defeat. He also looks the same as Piccolo Sr. because in addition to being his reincarnation, he's also his clone.
 * AIR revolves around the descendants of a samurai and a psychic (who, incidentally, also happen to be said couple reincarnated over and over) searching for the reincarnation of the one they failed to protect. However, unlike many other examples, they look nothing like their original selves.
 * The Big Bad in Tsukihime became a reincarnator as his own style of obtaining immortality, his mind/powers surfacing in one host after the other. His appearance/gender change freely with each appearance.
 * Several major characters in Yu-Gi-Oh! are reincarnations of people from ancient Egypt.
 * Seto Kaiba is the reincarnation of Priest Seto.
 * Yugi and Bakura Ryou are the modern-day reincarnations of Pharaoh Atem and Tozokuou Bakura, respectively.
 * Priestess Isis and Ishizu Ishtar.
 * Yu-Gi-Oh! GX also features reincarnation, in that.
 * Himeko and Chikane in Kannazuki no Miko are the reincarnations of the priestesses of the sun and moon.
 * Yoh and Hao in Shaman King are both reincarnations of the original Hao.
 * Eriol Hiiragizawa of Cardcaptor Sakura is the reincarnation of Clow Reed.
 * Reincarnation is one of the main themes of Osamu Tezuka's lifework, Phoenix.
 * It's a major theme in most of them, especially Houou (Karma in the U.S.), but it's actually a key element of Sun's unorthodox plot structure, which keeps flipping back and forth between past and future, with each time period being presented as the protagonist's "dreams".
 * In Elfen Lied manga epilogue,
 * In Princess Tutu, Fakir is revealed to be a knight from a fairytale "reborn" to protect his prince, who escaped from the story after the writer died before he could be completed. In the first season, he constantly struggles with trying to live up to the Knight while not having the same end (being torn apart by the claws of an evil Raven). In the second season, he slowly begins to give up on the role to take on his true calling as . He has a birthmark that looks like a scar from the wound that killed the knight to confirm his identity.
 * The three younger knights in Prétear are implied to be reincarnations of three knights that were killed during a battle—we see the knights in flashbacks, and although their faces are always obscured they have the same outfits and hair.
 * The plot of Please Save My Earth revolves around this, and includes a female character who reincarnated male in order to be able to have a happier relationship with the reincarnation of the man she had unrequited feelings for, and two characters who reincarnated into look-alikes of each other. Except for one example, they don't look like the characters they reincarnated from.
 * In one of the final episodes of Sister Princess, sorceress Chikage reveals to her brother Wataru that they had been lovers in a previous life.
 * All of the high school warriors in Ikki Tousen are reincarnations of the main characters in Romance of the Three Kingdoms. A lot of them wound up in perky girl's bodies, which doesn't seem to affect their bloodthirstiness—or their names—in the least. Of course, one wonders why some of the greatest strategists in Chinese history would bother fighting over the control of Japanese high schools in the first place.
 * In Otogi Zoshi, set in feudal Japan
 * Three of the four main characters in Saiyuki are reincarnations of gods who died protecting Son Goku.
 * The main antagonist of Immortal Rain is a soul that has been repeatedly reincarnated over the history of the Earth and remembers every single life leading to some... major mental issues and sparking the plot of the series.
 * Einhart Stratos of Magical Girl Lyrical Nanoha ViVid is the opposite gender reincarnation of Hegemon Klaus Ingvalt, being born with his silver hair, Mismatched Eyes eyes, pieces of his memories, and his will to establish hegemony over all lands and protect his domain. The last one's a bit of a problem for her since she's now living in a peaceful era where there's no country to defend.
 * The lesser-known manga Kagerou Nostalgia is based entirely around the idea of reincarnation. Six heroes are reincarnated as teenagers in order to try and take care of some unfinished business. Given the nature of the setting this sucks for them.
 * Bleach. When human beings die in the Land of the Living their souls go to the Soul Society (unless they change into Hollows) where they'll either be normal residents of Soul Society until they die again or become shinigami. Eventually they're reincarnated back into the human world.
 * One of the characters in Yumeria turns out to be the reincarnation of someone from the future, who came back to.
 * Gate 7 is a Urban Fantasy about characters of Sengoku era's reincarnations fighting to find the most powerful Oni of the world.
 * The whole point of That Time I Got Reincarnated as A Slime. A salaryman is murdered and is reborn in a High Fantasy world as a Blob Monster. Which it turns out, is not as bad for him as it sounds.

Comic Books

 * DC Comics: The original (and current) Hawkman and Hawkgirl were reincarnated lovers; Justice League Unlimited combined this and the Silver Age science-fiction version by making it unclear whether the memories of past lives were real or caused by a malfunctioning memory-recorder device (though a later episode seemingly implied the former). Recent comics make more of their continual cycle of reincarnation, destined to be killed when they find love with each other (hence the current versions, knowing this, keep each other at arms' length ).
 * Also continually reincarnated is their archenemy Hath-Set, who is the one destined to kill them. Their son Hector was reincarnated once, but has since
 * eventually ends up reincarnated at the end of Whatever Happened to the Caped Crusader? He is eventually reincarnated... as . The reward for being : You get to be.
 * Most of the cast of Camelot 3000 are the reincarnations of characters from Arthurian legend.
 * One of the more significant changes in IDW's incarnation of the Teenage Mutant Ninja Turtles is the role reincarnation plays in their origin. The turtles that became the TMNT, it turns out, were the reincarnations of four Japanese brothers murdered in ancient Japan. Splinter, who like in the original incarnation is a rat-turned mutant, is the reincarnation of Hamato Yoshi, their father, who before being slain prayed for a chance at revenge on their murderers.
 * In X-Men, this is Moira MacTaggart’s mutant power; whenever she dies, she is able to reincarnate herself, with her soul entering the body of a woman’s fetus - this allows her to be reborn as that woman's child, and upon reaching age 13 (the average age mutant powers manifest) she recovers all memories of all previous lives. (Her incredible genius in genetics and biology is the result of studying and researching far longer than would be possible in one human life.) She can choose when and where she is reborn, and can do so at any time in the past, meaning that the times she uses this power in present-day continuity, she is reborn in previous decades and takes The Slow Path to rendezvous with the X-Men, and she has managed to use this power to Set Right What Once Went Wrong more than once; Wolverine even killed her once in one story so she could do just that. There are limits to this, however. According to Destiny, the number of times she can be reborn is finite; she has “10, maybe 11 lives” (and she is currently on her 10th), and if she were to die before turning 13, she would die for real.

Fan Works

 * In Super Milestone Wars, Kamina from Tengen Toppa Gurren Lagann has been reincarnated as a pony living in Ponyville in Equestria.
 * Has been used as a plot point in DC Nation when it comes to the founding Titans. Dark Angel kidnapped Donna Troy to use as an experiment, sending her through Hypertime in a series of "short, unhappy lives." However, as Donna's incarnations lived, she found other souls with a similar spark to them, and acted as a kind of magnet to keep bringing them together through the centuries and lives.
 * In the My Little Pony: Friendship Is Magic fanfic Past Sins, the essence of Nightmare Moon gets reincarnated as a timid filly that Twilight Sparkle adopts and names Nyx. Then things get interesting from there...
 * In Night of the Seance, found herself in the intermediate state since she was to be reincarnated due to her violent death. Simon thought such concept wasn't part of Christian system until the French priest and Andy explains there is a passage in the Bible that says else-wise.
 * In WWE FanFic Cruising for a Jobbing, Charlotte discovers her opponent, Anna II, happens to, the woman she made fun of on social media. Charlotte's punishment....

Films

 * "Reincarnation" as a plot device is pretty common in the Indian Cinema industries, to the point of being a cliché. Just note how many indian productions are in the Wikipedia category "Films about reincarnation"
 * In the Bollywood movie Om Shanti Om, Om is reincarnated and looks exactly like he did in his previous life — complete with his tattoo becoming some sort of birthmark.
 * Dead Again: It becomes apparent that the protagonists are reincarnated spirits of murder victims.
 * The romantic comedy Chances Are has a reincarnated man romancing his own widow.
 * In Fluke, it starts with the main character being reincarnated.
 * The plot of Audrey Rose centers on this.
 * The Mummy Returns makes use of this; O'Connell is the reincarnation of a member of the medjai, Evie is the reincarnation of an Egyptian princess, and Imhotep is brought back by the reincarnation of Akh-sun-Amun.
 * In the Albert Brooks comedy Defending Your Life, people have to go before a panel of judges and prove that they're enlightened enough to move on to Heaven. If they fail to do that, they're sent back to Earth to get it right the next time.
 * In The Return of Hanuman is quite different as it doesn't involve death (but quite common in Hinduism), the main protagonist Maruti is the reincarnation of Hanuman.
 * A particular version of the trope is used in Jupiter Ascending: the titular Jupiter happens to be genetically identical to the deceased matriarch of a galactic dynasty, and everybody who knows treats this as if the woman actually reincarnated. Given that said galactic dynasty is a Big Screwed-Up Family with several unsolved issues towards their mother, things doesn't paint well for poor Jupiter.

Literature

 * In The Wheel of Time series, people who become legendary heroes are put on a special track of reincarnation, each life resembling the other and creating its own batch of legends. They hang out in the World of Dreams between lives and are forbidden from interacting with mortals. Everyone else is also reincarnated but are of less central importance to the pattern. The Dragon Reborn is unique in that everyone knows who he is a reincarnation of, when even those who have also lived past lives as great heroes cannot be identified and rarely discover this for themselves.
 * Kim Stanley Robinson's epic novel The Years of Rice and Salt has the protagonists in a cycle of eternal reincarnation in order to explore 1000 (or more) years worth of history if the black death had killed all of Europe. In line with the original concept the True Companions play out different roles, relationships and genders (although their names always have the same first letter) in different reincarnations.
 * In Dragaera, reincarnation is a fact of "life." For instance,
 * This is the essential theme of Katharine Kerr's long-running Deverry series, which feature a "present day" plot along with multiple parallel flashbacks featuring previous incarnations of the same characters. Later books often include a chart to keep track of them all.
 * One story by Science Fiction writer F.M. Busby used Reincarnation, a Gender Bender and two Stable Time Loops to combine Truly Single Parent with Screw Yourself: The protagonist is reincarnated twice, first as his wife and later as their daughter. It makes you wonder why she never said anything.
 * On Discworld, you are (possibly) guaranteed reincarnation if you die while possessing a potato, though not necessarily a human incarnation. The abbot of the History Monks also practices reincarnation, and in his second appearance (Thief of Time) is a baby.
 * You don't always have to believe in reincarnation for this to happen. Reincarnation just has to believe in you.
 * The novel Avalon High has its characters be High School renicarnations of King Arthur, his knights, and his associates.
 * H. Beam Piper believed in reincarnation, and wrote a Paratime novel examining what would happen if everyone had concrete proof it happened. (One fission bomb was dropped when the paratimers got involved. The general feel was "an interesting place to visit, but unless you can adopt a particularly accepting attitude towards your own death, you wouldn't wanna live there.")
 * The T'swa in John Dalmas' The Regiment also consider reincarnation a given, and their attitude resembles that mentioned in the Piper example above. Men who regard their own deaths as only a minor inconvenience can be very effective fighters. Reporter Varlik Lormagen adopts some of their ways of thought; a dream he has late in the book suggests that.
 * I've Been Waiting for You is of the "past events play out in the present" subtype, but with a strong emphasis on Screw Destiny—the protagonist was one of the girls whose accusations kicked off the Salem witch trials, and she has no intention of repeating the slaughter.
 * Waking Echoes has the Visions of Another Self kind, only it's the incarnation that's traveling.
 * In An Elegy for the Still-living, Robin claims that he and Francis are reincarnations of Gilgamesh and Enkidu, and that they have died and been reborn countless times throughout the ages, possibly as other fictional characters who fall under some of the same archetypes.
 * In Warrior Cats, Cinderpelt is reincarnated as her own niece, Cinderheart, who was born at the same instant Cinderpelt was killed defending the mother from a badger. She was given a second chance at life because the first time around, she was caught in the villain's trap and injured by a car, preventing her from becoming a warrior. Cinderheart eventually lives Past Life Memories in her dreams, and realizes who she is.
 * In the Low Fantasy Neustria trilogy by Leslie Barringer, one of the few explicitly fantastic scenes is the ghost of a young woman appearing to the coven of which she used to be a member -- and she says of the young man she failed to win, "I might not be his woman, but if I watch and wait I may yet be the child of his love." She's going to try to be reborn as the daughter of the man she loves....

Live-Action TV

 * Lois and Clark had an episode with Superman and Lois Lane as reincarnated lovers (explaining that Superman's soul was from beyond time and distance), and had them time-travel to their past-life bodies to undo an ancient curse.
 * It even hits the soap operas: one 90's Brazilian soap titled A Viagem, based in spiritist theories, has the main couple being lovers from their past lives, and they fall in deep love again in their actual incarnation. The little fact that they die midway the story didn't stop their affair, as they encounter each other again in the afterlife by the sheer force of their love, and the finale pointed that they will reincarnate and find each other again.
 * Speaking of soaps, the original Dark Shadows used this trope heavily, along with every other excuse they could think of to keep casting the same actors in different time periods and dimensions.
 * The premise of Mada Koi wa Hajimaranai, a dorama series from 1995, where the story revolves around a pair of reincarnated lovers from 200 years ago, and whether or not they'll get together this time around.
 * Xena: Warrior Princess does this a lot, including a very funny episode where an obsessive Xena fan (played by Lawless) turned out to be the reincarnation of Joxer.
 * The Minbari of Babylon 5 believe in reincarnation in a semi-closed system where the same pool of souls is constantly reborn. This is a key plot point in several ways.
 * The X-Files episode "The Field Where I Died". Mulder comes to believe that he was married to a female member of a cult in a past life, and under hypnosis claims to remember not only her but Scully and Cancer Man as reincarnated friends and enemies respectively.
 * In Red Dwarf, Arnold Rimmer claims that in a previous incarnation, he was Alexander the Great... -'s Chief Eunuch.
 * On Green Acres Eb is missing, and a stray dog shows up. Naturally Lisa thinks the dog is Eb "reincarcerated" ("reincarnation" means when you come back as a flower).
 * Played for laughs in an episode of Round the Twist, where Linda hypnotises her brother back into a past life in the hope he'll better be able to complete his do-it-or-you're-suspended homework. When his previous incarnation starts trashing the house, she hypnotises the baby she's sitting to his previous life as a wrestling champion, only making things worse. Ultimately its the once Oxford University professor, their chicken, who helps them complete their homework.
 * Turned up occasionally in Charmed. One episode reveals that the sisters are all reincarnations of their own ancestors. Due to Time Travel, Paige once got in a fight with her own past life. The "looking exactly like your past life" thing is explained to be due to their "souls recognizing each other", making them see each other as their current selves during a past-life regression.
 * Implied in Seven Days. One episode had a villain with a birthmark under one eye. He got killed, and the episode ends with a shot of a newborn baby with the same birthmark under his eye.

Music

 * Ronnie Lane's "Stone" aka "Evolution" tells of a different birth (first person) in each verse.
 * The song Gonzo sings in The Muppet Movie, "I'm Going To Go Back There Someday" can be interpreted as being about reincarnation.
 * In Dream Theater's Metropolis, Pt. 2 album, the protagonist discovers that

Radio

 * Averted in "Fredrickism", a skit by Hudson and Landry about a Scam Religion. When asked if Fredrickism believes in reincarnation, founder Freddie Schultz says they don't need to: if you follow all 26 Commandments then you never die.

Tabletop Games

 * The Freedom City setting for Mutants and Masterminds has The Scarab, a superhero who was originally the Pharoah Heru-Ra. Like Hawkman, he is destined to be killed by the reincarnation of the priest who killed him the first time, Tan-Aktor, who is currently Overshadow, the setting's Supreme Hydra Captain Ersatz.
 * The world of Exalted works under a system of reincarnation, with a person's "higher soul" entering into the spin cycle until it's abandoned all memories of its former life. However, the titular Exalted effectively receive another soul at the moment of their Exaltation, and receive flashes of the life the previous bearer led.
 * The Alchemical Exalted put a different spin on this: each Alchemical Exalt is created using a higher soul that has proven itself heroic in multiple lives. An Alchemical is basically a whole new incarnation, but incorporating characteristics (and potentially memories) of their previous lives.
 * Part of the backstory of Warhammer 40,000 is that in humanity's distant past, the first human psykers had the ability to reincarnate, allowing them to accumulate power and knowledge over several lifetimes to continuously protect the human race. However, as civilisation progressed, the Chaos within the Warp grew strong enough that reincarnation became increasingly difficult, to the point where it would have been impossible. The psykers decided to avert this disaster by committing mass suicide and all of them reincarnating into a single body. The person born from this became the God-Emperor.
 * This explanation was Canon in the early editions, but recently, its been changed to just one of many possible theories.
 * The almost-forgotten Man, Myth & Magic was based on this. Aim of the game: Reincarnate at least once in every possible Character Class, and remember your incarnations in all of them.
 * Kult has both reincarnation and a heaven/hell system, a bit like Greek mythology (though rather simpler.)
 * Reincarnate is a spell in Dungeons & Dragons. It causes a deceased recipient to come back to life in a new body, often of another species (for instance, a human coming back as an elf or orc).
 * Fire Born actually uses this as a core mechanic, interestingly they do this by making you jump between your current incarnation and your previous ones.
 * It is actually stated in the source books of the game that Reincarnation is part of the draconic life cycle

Theater

 * Daisy, the main character of the Musical On A Clear Day You Can See Forever, is actually the reincarnation of a woman named Melinda Welles, which her therapist discovers when he puts her under hypnosis. Inevitably he falls for Melinda.
 * In The Adding Machine, it's explained by Lieutenant Charles that souls get recycled until they're worn out, because it's not worth making one just to use it once. Zero has been there at least fifty thousand times before, and each time he went back he got worse.

Videogames
"Fi:"
 * Link and Zelda in every Legend of Zelda game are theorized to be reincarnations of the original Link and Zelda from Skyward Sword. While Zelda is always reincarnated in her own bloodline, Link can be anyone, though somehow he always looks similar to his predecessors. Link and Zelda are always reincarnated at about the same time and they are always the respective bearers of the Triforces of Courage and Wisdom. Even their personalities can vary, but they usually don't. The notable exception is Tetra, who is the Wind Waker incarnation of Zelda; having been raised by pirates, she's a bossy tomboy. She's still a worthy carrier of the Triforce of Wisdom, since she's just as smart as all past Zeldas.
 * In Skyward Sword, . It also raises the possibility of reincarnation applying to :


 * This topic is directly brought up in The Wind Waker, where the guardian spirits of Hyrule speculate as to whether Link is actually the reincarnation of the Hero of Time.
 * Spirit Tracks shows that it certainly applies to the Lokomo.
 * The Hyrule Historia artbook reveals that the Ganondorf in The Legend of Zelda Four Swords Adventures is a reincarnation of the one from Twilight Princess; this is explained by the fact that.
 * The entire main cast in Tales of Innocence. The main character, Ruca, was a general named Asras on one side of a war in Heaven dedicated to capturing the "Souseiryoku" and reuniting Heaven with Earth. Throughout the entire game, the characters explore the distinction between themselves and their past lives, with a climax in which
 * The point translates into gameplay, as every reincarnated person can assume their original form through a process called "Awakening", and each main character's Awakening is their Hi-Ougi.
 * Of course, the big reveal in Castlevania: Aria of Sorrow is that is the Reincarnation of  The original Aria game left some wiggle room over what that meant, but the sequel solidified it.
 * Fei and Elly from Xenogears.
 * In Okami, Amaterasu is the reincarnation of Shiranui.
 * may be this towards Sonic.
 * Fae and Arasai (an Evil Twin race) from EverQuest II all go through this process, so long as their spirit bud remains intact in-between lives.
 * Disgaea:
 * In many Nippon Ichi games, reincarnation is a vital tool to power up your Player Mooks, you can even reincarnate the hero but he will still have the same form he did before reincarnating.
 * Reincarnation is a central theme of the Soul Blazer trilogy, for the hero and the many creatures he interacts with. Blazer is implied to have been reincarnated many times in the service of The Master (Deathtoll calls him a "creature that suffers eternal transmigration of the soul and cannot die"), and Will and his friends reincarnate and meet each other at the end of his journey. Terranigma's Ark has reincarnation play out for him in a horribly depressing way.
 * Souls can be reincarnated in Afterlife, provided they believed in it before they died. This is achieved by chucking them through a glowing portal-nexus-thingy situated halfway between heaven and hell, which in turn is accessible by a special soul train.
 * A fairly common fan theory for Planescape: Torment is that the Nameless One is the reincarnation of Zerthimon, the first Githzerai.
 * Hieda-no-Akyu from Touhou. It's part of her perpetual duty to record the history of Gensokyo. She will always be reborn into the Hieda line, with the down side of having weak body. Her first incarnation, Hieda-no-Aichi, supposedly penned the Kojiki.
 * Seems to be subverted in Rhiannon: Curse of the Four Branches, in which the villain evidently thinks all four women named "Rhiannon" are the same person reborn. But if he's right about that, how can the ghosts of the previous three Rhiannons all be simultaneously haunting the home of the current one?
 * Subverted and played straight in Devil Survivor.
 * In Silent Hill 3,  is revealed to be a reincarnation of  . There's also.
 * In Agarest Senki 2,
 * Lufia 1 & 3, the blue haired heroines are both reincarnations of, and both are in love with the red headed heroes with the same blood line. Since Lufia 3 is a sequel, this means the history repeats itself.
 * Asura's Wrath.
 * The Ur-Quan Kohr-Ah in Star Control II believe in reincarnation. There's no evidence to show that this is actually the case, however.

Webcomics

 * Aleksander and Alison from My Life in Blue have been reincarnated together many times over the ages, brutally dying every time.
 * Something*Positive has.

Web Originals

 * Sasha Hunter of Greek Ninja is in fact the reincarnation of Eli of Thrace, a mythological hero.

Western Animation

 * In Avatar: The Last Airbender, every time the Avatar dies, he or she is reincarnated. It isn't specified how many Avatars there have been, but it is implied that Aang is at least the one thousand and first Avatar. To quote Avatar Roku, "I have mastered the elements a thousand times in a thousand lifetimes, and now I must do it once more." Of course, he could have simply been using the number 1000 to express that there have simply been a vast number of avatars, just as the name "He who knows 10,000 things" idiomatically means knowing everything. It is also stated that if he is killed during The Avatar State there will be no more reincarnations.
 * The reason for this is actually a curious idiosyncrasy. Aang is the reincarnation of all the Avatars before him, but each Avatar is nonetheless a unique individual, and rather than recycle the same soul over and over as in most conceptions of reincarnation, they appear to each have a unique soul which is linked to that of the other Avatars in some strange metaphysical way. The reason the Avatar Cycle will end if Aang is killed in the Avatar State is that in this state, the souls of all the previous Avatars have come on board to lend him their power, so if he's killed then, all the previous Avatars are basically dying twice.
 * To be more precise, there are two beings: the Avatar "spirit" and the human soul it inhabits. Every Avatar is indeed an individual person, the only thing tying them together is the avatar spirit who moves to another body once it's "host" dies.
 * Previous Avatars are invariably referred to as Aang's "past lives". Each incarnation of the Avatar is distinct, certainly, but only insofar as each is a unique expression of a single soul, which is absolutely in line with most conceptions of reincarnation. During the timeframe of the original show, Avatar Aang is uniquely Aang rather than, say, Roku... but he still used to be Avatar Roku in his previous life, and a part of him always will be. So, strictly speaking, the Avatar State does not involve a legion of souls "[coming] on board" but rather the totality of lives lived by a single soul manifesting simultaneously within its present incarnation.
 * That being the case, what we learn of the previous Avatars' characters can also easily be seen in Aang's own character. But it's so broad (judgement, mistakes, irresponsibility, relationships) that it could also be taken as the 'human' aspect of the Avatar spirit rather than any specific connection to his predecessors.
 * Also, such a soul as the Avatar's might be an extremely flexible in how it is expressed. Think about it; if you can master all four elements, why can't you manifest a million different personalities?
 * There is one similarity between all the Avatars - some of them were lazy and irresponsible, some of them were hesitant to carry out their duties, and some of them were cool and distant, but all of them were committed to protecting the people of the four Nations. Each Avatar has displayed a level of selflessness and empathy towards their fellow man that far exceeds that of most other people. So no matter how its current gender, culture, time period, and lifestyle change the Avatar's outward personality, it will always be protective and loving to the mortals for which it repeats the cycle.
 * It is also implied that reincarnation is the ultimate fate for everyone in the ATLA universe, not just the Avatar. This corresponds to the traditional Hindu and Buddhist beliefs the show took inspiration from.
 * A scrapped storyline that had been toyed with involved Momo the flying lemur being Monk Gyatso's reincarnation. The reason this ultimately didn't happen is most likely because reincarnating into an animal is typically a sign that the soul did some great and terrible evil in its previous life.
 * The Sequel Series The Legend of Korra stars Korra, the newest Avatar and the reincarnation of Aang. The plot eventually explores how the circle began in the first place
 * The Twist Ending in this short film "Get Out"
 * Sometimes referenced by Hindu character Apu in episodes of The Simpsons. In one episode, as he's getting ready to hang himself, he looks at a "reincarnation chart" to see what he'll be in the next life. In a Treehouse of Horror episode parodying The Most Dangerous Game, he dies but immediately reincarnates as a rabbit.

Real Life

 * Famous American general George S. Patton believed that he had been reincarnated several times prior to his "current" life. He even believed himself to be the reincarnation of Hannibal (not that Hannibal).
 * Between ten and twenty percent of Britons with a "traditional" Western religious background (ie. not including Hindus, Buddhists etc.) apparently believe in reincarnation.
 * Ironically, it's been said there are more people who believe they were on the Titanic in a past life than there were actual passengers.
 * Part of many religions and many new age groups.
 * The Dalai Lama, who is believed to be living his fourteenth life as Tenzin Gyatso.