Doppelgänger

Doppelgängers, also known as Shadow-Selves or Mortal Shadow Selves, are a supernatural occurrence that were created by Nature as a result of Silas, Amara, and Ismene becoming true immortals after consuming Qetsiyah's immortality elixir. The purpose of this supernatural species is to maintain the natural balance by dying in place of their immortal progenitors. For this reason, doppelgängers have existed for at least 1,000 years during which time they have been born and died in the place of Silas, Amara and Ismene, who, as true immortals, were invulnerable to any conventional weapon.

There are three known doppelgänger lines which stem from Silas, Amara, and Ismene, respectively. Known doppelgängers of Silas are Stefan Salvatore and Tom Avery; known doppelgängers of Amara are Tatia, Katerina Petrova, and Elena Gilbert; and known doppelgängers of Ismene are Daria, Adyelya Petrova, and Clara Gilbert.

Creation
The phenomenon of the shadow-self occurs to counterbalance a disruption to Nature's law that all living things must die. Qetsiyah, one of the most powerful witches and member of a very gifted people called the Travelers, created a spell for immortality with the intention that she and Silas would drink it together at their wedding. However, Silas stole the immortality elixir and used it on himself and his lover, Amara (and Amara's twin sister Ismene, who Amara can't live without.), who was Qetsiyah's handmaiden, so that the three could be together for eternity. Disrupting the balance of Nature when they became truly immortal, Nature eventually began to create doppelgängers of Silas, Amara, and Ismene that could die to counter the balance that was disrupted by these new immortals.

Silas, Amara, and Ismene: The World's First Immortals
Over two thousand years ago in ancient Greece, a young witch named Silas was engaged to be married to Qetsiyah, also a fellow witch. Together, they were the most powerful members of a gifted people called the Travelers. Silas told Qetsiyah that he wanted their love to last forever, even beyond death, and he convinced her to create a spell that would make them immortal. On the night that their wedding ceremony was to take place, Silas absconded with the elixir Qetsiyah had created, and as Qetsiyah watched the plant life around her wither before her eyes, she realized that not only had Silas taken the elixir and left her at the altar, he had also given her portion to someone else. She sought out Silas and found him in the wilderness with another woman – her handmaidens, Amara and her twin sister Ismene - who had taken Qetsiyah's share of the immortality elixir.

Silas and Ismene, having left Amara alone for an unknown reason, returned to their hiding place to find Qetsiyah crouching over the chalice that had held the elixir they were to drink at their wedding. He cautiously inquired after Qetsiyah's purpose for being there, so she explained that, to follow up her first gift of the immortality elixir, she had brought a second gift: The Cure for immortality. Silas was dumbfounded, hardly believing her, but she insisted that it worked, as she had already used it on another immortal. Filled with dread, Silas ran into the tent he had shared with Amara and Ismene, only to find blood soaked into every surface, as though someone had been brutally slaughtered there. Qetsiyah followed him into the tent and lifted a bloody human heart out of the chalice, admitting that she had slit Amara's throat before ripping her heart out. She then gave him an offer to take the cure and spend the rest of his human life with Qetsiyah, an offer that Silas refused.

In retribution for betraying her, Qetsiyah used the eternal and indestructible body of Amara (whose death she had faked just prior to using magic to desiccate her into stone) to create the supernatural purgatory known as the Other Side. She then lured Silas to an island off of what is now Nova Scotia, Canada, where she trapped him inside a tomb and gave him a choice: he could take the cure and eventually die a mortal death (which would then cause him to pass on to the Other Side, where he would be trapped with her for eternity in the afterlife) or he could stay immortal and starve into petrification for the rest of his immortal life. Silas ultimately chose the latter and desiccated for the next two thousand years while the cure was left untouched. Silas made it so Ismene was able to get away and Ismene succeeded in getting away and was never found by Qetsiyah.

One major consequence of Silas, Amara, and Ismene becoming immortal was the creation of three lines of shadows-selves, or doppelgängers of the three immortals. Their immortality had violated Nature's law that all living things must die, and so the doppelgängers came to exist as versions of Silas, Amara, and Ismene that could die. According to Qetsiyah, many identical replicas of Silas, Amara, and Ismene have been born over the centuries, finding each other time and time again as though drawn together by destiny. However, it was later revealed by a fellow Traveler, Markos, that he had cast the spell on the two of three respective lines of doppelgängers to draw them together so they could eventually break the curse on their people by harvesting the blood of the sole remaining doppelgängers of the two of three line.

Powers and Abilities

 * Blood: Doppelgängers, being mystical and recurrent, are massive sources of magical power.
 * The blood of a doppelgänger can be used to link supernatural beings with the help of magic conducted by any witch.
 * Their blood can also be used to bind an extremely powerful curse or spell or to use as a power source in spells that require more magic than the witch in question possesses on their own.
 * For some spells, the blood must come from a human doppelgänger. For other spells, the blood of a doppelgänger can still be used even if they've been turned into a vampire, as seen in Death and the Maiden when Qetsiyah used Elena's blood (along with Katherine and Amara's blood) to transfer the Anchor from Amara to Bonnie. There are certain spells and uses that require the doppelgänger to be "pure" and human, however, like the undoing of the Hybrid Curse and the siring of hybrids.
 * The blood of the last two "living" doppelgängers can be used to reverse spells cast using non-traditional forms of magic, especially Spirit Magic (e.g. turning a vampire back into a (dead) human, undoing the spell that bound the Other Side, reversing the spells cast on daylight rings for vampires, removing a triggered gene in those cursed with lycanthropy, etc).


 * Linking: Doppelgängers, being modeled after immortals and other doppelgängers, have an inherently strong mystical connection to each other that can be used to invoke linking spells.
 * Unique Physiology: Doppelgängers are fully capable of being turned into vampires, and can retain the mystical properties of their blood despite their vampiric abilities. Since they can also be born witches, as in the case of Katerina Petrova, it can be assumed that doppelgängers could theoretically also be born as other supernatural species, such werewolves or Brotherhood of the Five hunters.

Weaknesses

 * Magic: Doppelgängers are susceptible to the powers of witchcraft. This is inclusive of mystical objects such as Papa Tunde's Blade, and Dark Objects.
 * Mortality: Despite of their supernatural status, doppelgängers are very much human and share many of the same weaknesses as non-supernatural beings (e.g. age, decapitation, disease, heart-failure, suffocation, etc.)

Amara's Doppelgängers
Amara's doppelgängers are Tatia, Katherine, and Elena, all three of which have appeared on-screen. Elena is sometimes referred to as the Petrova doppelgänger because of her striking resemblance to Katerina Petrova.

Silas' Doppelgängers
Compared to the Petrova Doppelgängers, the Salvatore Doppelgänger do not seem to be as recognized, since Klaus and Rebekah seemed to have failed at recognizing Stefan for what he was during the early 20th Century, other than an emotionless Vampire at the time(riper).

Ismene Doppelgängers
Ismene's doppelgängers are Daria, Alice, and Clara, all three of which have appeared in on-screen.

Doppelgänger Myths, Facts and Theories

 * A Doppelgänger is the ghostly or in some cases, a physical double of a living person. The word Doppelgänger is a loanword from German, written there (as any noun) with an initial capital letter Doppelgänger, composed from doppel, meaning "double", and ganger, as "walker". In English, the word is conventionally not capitalized, and it is also common to drop the German diacritic umlaut on the letter "a" and write "Doppelgänger", although the correct spelling without umlaut would be "doppelgaenger".
 * In some traditions, when a doppelgänger is seen by a person's friends or relatives, the contact prophesies illness or danger, while a person seeing their own doppelgänger is an omen of death.
 * In other traditions or legends, a doppelgänger is connected with the person copied; sometimes causing the feelings of injuries between the original and the doppelgänger. For example, if the doppelgänger is injured, the other person will also be hurt or feel pain.
 * "Doppelgänger" is a German word or term meaning "double walker" or "double goer"―a shadow self that is thought to accompany every person. Traditionally, it is said that only the owner of the doppelgänger can see this phantom self and that it can be a harbinger of death. Occasionally, however, a doppelgänger can be seen by a person's friends or family, resulting in quite a bit of confusion.
 * 'Definition of a Doppelgänger varies between the accounts of the old ages. They were mentioned as double spirits of human beings since the very old times. They were also mentioned as apparitions or reflections of people. Although they looked exactly the same or indistinguishably similar with the person they impersonated, Doppelgängers were not twins of these people. It was stated in some mythological accounts that Doppelgängers cast no shadows and had no reflections in the mirror.
 * The term "Doppelgänger" is used often to describe someone that looks just like (or at least very similar to) another person, but there are more mysterious and sinister roots than the word suggests.
 * Literally meaning "double-goer", a real Doppelgänger is an apparition that appears in place of a person in a location or situation that would not otherwise be possible. Many people have seen this image of themselves, both in life and in visions. Other times, a person may be seen walking through a room when they are, in actuality, several miles away at the time. The third most common sightings occur when the image of a person appears to walk past an area twice in a row - moving in the same direction - to where it would be impossible for the person to have returned there fast enough.
 * A Doppelgänger is a creature who has the ability to mimic any human being's appearance and characteristics. Usually a Doppelgänger chooses a particularly wealthy person to impersonate, being that they are lazy and would rather have resources already for them. Occasionally, but not always, a Doppelgänger has a larger, more detailed plan for why they would impersonate a person. This often makes them seem "evil" or "malevolent".
 * According to legend, Doppelgängers (German for “double-walker”) are paranormal duplicates of a real person. They can manifest in a number of ways: You can see them out of the corner of your eye, meet them on a lonely road somewhere, or, chillingly, see them standing behind you when looking in a mirror. Sometimes a Doppelgänger can’t be seen by the person at all, but instead manifests to other people in a completely different location. It may even cooperate with the person, help them with tasks, or act as a surrogate body of sorts.
 * The term has, in the vernacular, come to refer to any double or look-alike of a person, most commonly in reference to a so-called evil twin, or to bilocation. Alternatively, the word is used to describe a phenomenon where you catch your own image out of the corner of your eye. In some traditions, seeing one's own doppelgänger is an omen of death. A doppelgänger seen by friends or relatives of a person may sometimes bring bad luck, or indicate an approaching illness or health problem.
 * The doppelgängers of folklore cast no shadow, and have no reflection in a mirror or in water. They are supposed to provide advice to the person they shadow, but this advice can be misleading or malicious. They can also, in rare instances, plant ideas in their victim's mind or appear before friends and relatives, causing confusion. In many cases once someone has viewed his own doppelgänger, he is doomed to be haunted by images of his ghostly counterpart.
 * Some accounts of doppelgängers, sometimes called the ‘evil twin’ suggests that they might attempt to provide advice to the person they shadow, but that this advice can be misleading or malicious. They may also attempt to plant sinister ideas in their victim’s mind or cause them great confusion. For this reason, people were advised to avoid communicating with their own doppelgänger at all costs.
 * Other folklore says that it is considered unlucky to try to communicate with a doppelgänger.
 * In Ancient Egyptian mythology, a "ka" was a tangible "spirit double" having the same memories and feelings as the person to whom the counterpart belongs. In one Egyptian myth entitled, "The Greek Princess", an Egyptian view of the Trojan War, a "ka" of Helen was used to mislead Paris of Troy, helping to stop the war.
 * In Norse mythology, a "vardøger" is a ghostly double who precedes a living person and is seen performing their actions in advance. In Finnish mythology, this is called having an "etiäinen", i.e., "a first comer". Norse folklore describes entities known as vardøger, ghostly beings that preceded their living counterparts, taking their places at various activities and performing their actions in advance. The spirit with the subject's footsteps, voice, scent, or appearance and overall demeanor precedes them in a location or activity, resulting in witnesses believing they've seen or heard the actual person before the person physically arrives. This bears a subtle difference from a doppelgänger, with a less sinister connotation.
 * “Vardøger” (vardøgr or varsel) in Norse mythology can be considered as another reference to Doppelgängers. A vardoger was the ghost-like double spirit of a person which was seen doing the actions of a person before he did it, kind of like a reverse déjà vu that actually happens.  In Norse mythology it was also interpreted that these beings might be some kind of bilocation (existing at two locations at the same time) as well as guardian spirits for a human being.
 * In Breton mythology as well as in Cornish and Norman French folklore, the doppelgänger is a version of the Ankou, a personification of death.
 * Doppelgängers were once thought of as aliens who would land on earth in order to execute a plan to invade the human race and replace every person with a look-alike Doppelgänger. This is not the case. Doppelgängers, like most other mythical creatures, have some tie to the human race. They are not a different species altogether, but rather a hybrid.

Trivia

 * Silas and Amara's doppelgängers may not be limited to a continuous 500 years recurrence as it has been speculated since Season Five.
 * In Original Sin, Qetsiyah stated that "century after century", she watched versions of Stefan and Elena find each other and fall in love—this could mean that Klaus only presumed that Petrova doppelgängers only appeared every half-millennium or so because it took him that long to find one after losing Katherine. However, it is also possible that Qetsiyah's statement was meant to be hyperbolic to emphasize the misery she felt watching the shadows of Silas and Amara continue to find love while she was trapped on the Other Side.
 * According to Qetsiyah, the shadows of Silas and Amara are destined to find each other and fall in love, based on her observations throughout the centuries. It is unknown if Qetsiyah saw versions of Silas and Amara fall in love when they were alive or if they died and fell in love on The Other Side. However, evidently, they are also capable of developing romantic feelings for other people. Examples include:
 * Stefan and Rebekah
 * Elijah and Katherine
 * Elijah and Tatia
 * Elena and Matt
 * The term doppelgänger doesn't seem to imply any hierarchy.
 * Qetsiyah has, in one instance, mentioned Silas as Stefan's doppelgänger.
 * Silas himself referred to Amara as Elena's doppelgänger.
 * Silas and Stefan can be called doppelgängers of each other. Similarly, Tatia, Katherine, Elena and Amara are all doppelgängers of each other since they are all lookalikes of each other.
 * The term "Shadow" has some implied hierarchy as opposed to doppelgänger.
 * Katherine referred to Elena as her shadow-self and Silas did the same to Stefan.
 * Elena is the shadow of Amara, Tatia and Katherine, while Katherine is that only of Amara and Tatia.
 * Doppelgängers are humans for most intents and purposes. However, they are a supernatural occurrence and are therefore, considered to be a supernatural species. The difference between regular humans and doppelgängers is that spells that use a doppelgänger can be broken using another doppelgänger.
 * Death by a doppelgänger counts as a supernatural death. A person wearing a Gilbert Ring will come back to life if killed by a human doppelgänger.
 * The Gilbert rings do not protect supernatural creatures and is, thus, theorized not to work on a doppelgänger. This has never been confirmed.
 * They can, however, be compelled by vampires like any regular human.
 * It seems that the men who spend a lot of time with doppelgängers of Amara can't help but fall in love with her or fall vulnerable to her charms. Back in the 11th century, it was stated that every man in the village fell in love with Tatia, though Elijah and Niklaus Mikaelson more than any others. Trevor, Elijah, Damon Salvatore, Stefan Salvatore and Mason Lockwood all fell in love with Katherine, and Noah was obsessed with her. Matt Donovan and Stefan Salvatore fell in love with Elena.
 * Similarly, it seems that many women also find themselves strongly attracted to Salvatore doppelgängers. An example is Elena, Bonnie, Caroline, Katherine, Qetsiyah and Rebekah all finding Stefan appealing and all of them being attracted to him at one point or another. It could easily be assumed that Silas was also very attractive to the opposite sex as well, since he had two women who were passionately in love with him (and one psychotically so) in Qetsiyah and Amara.
 * Katherine and Elena both became vampires, though Katherine was cured of her vampirism and returned back to a human/witch before eventually dying of old age.
 * Silas and his doppelgänger, Stefan, have first names beginning with the letter "S". It is unknown if other doppelgängers of Silas also had names beginning with the letter S.
 * Tom Avery, the second known doppelgänger of Silas (who is assumed to be the final doppelgänger of the line) seems to break this tradition, as his name begins with the letter T.
 * All of the known shadows of Amara, like herself, have first names that rhyme with each other. All of the known Petrova doppelgängers, including the progenitor Amara, have first names which end with an "A" (AmarA, TatiA, KaterinA, ElenA).
 * A doppelgänger will look identical in appearance to their immortal progenitor, but there will be variations in both their looks and their personalities due to differences in their rearing and community standards (such as their expressions, speech, reason, and connections with others), especially as a result of them all being born in different time periods. For example, the timeline of the progenitors of the line and their shadow-selves is as follows:
 * Silas (Progenitor/Originator of Salvatore Doppelgänger bloodline): Born some time in 1st Century BCE in Ancient Greece
 * Ismene (Progenitor/Originator of the second Petrova Doppelgänger bloodline): Born some time in 1st Century BCE in Ancient Greece
 * Amara (Progenitor/Originator of Petrova Doppelgänger bloodline): Born some time in 1st Century BCE in Ancient Greece
 * Daria (1st Petrova Doppelgänger of the second bloodline): Born in the late 900's CE in the New World (now Mystic Falls, Virginia, USA)
 * Tatia (1st Petrova Doppelgänger): Born in the late 900's CE in the New World (now Mystic Falls, Virginia, USA)
 * Adyelya Petrova (2nd Petrova Doppelgänger of the second bloodline): Born in 1473 in Bulgaria
 * Katerina Petrova (2nd Petrova Doppelgänger): Born in 1473 in Bulgaria
 * Stefan Salvatore (2nd Salvatore Doppelgänger): Born in 1846 in Mystic Falls, Virginia, USA
 * Tom Avery (3rd/Final Salvatore Doppelgänger): Born in the late 20th century in the USA (possibly Atlanta, Georgia)
 * Clara Gilbert (3rd Petrova Doppelgänger of the second bloodline): Born in 1992 in Mystic Falls, Virginia, USA
 * Elena Gilbert (3rd/Final Petrova Doppelgänger): Born in 1992 in Mystic Falls, Virginia, USA
 * According to some myths, doppelgängers tend to undo the lives of each other. Tatia was used to create the Original Vampires but her doppelgängers have influenced the deaths of all three deceased Original Vampires.
 * Katherine distracted Mikael, which let Klaus have a shot at his heart.
 * Elena shot Finn with a crossbow to disable him for a few moments before Matt killed him.
 * Elena held down Kol, after weakening him with vervain, thus allowing Jeremy to kill him.
 * Now that Stefan has been revealed to be a doppelgänger of Silas, in retrospect, it seems more than just a mere coincidence that Stefan too influenced the deaths of the three Original Vampires.
 * Stefan intervened when Damon tried to take a shot at Klaus, which led to the death of Mikael.
 * Stefan took the first shot at Finn and was disarmed immediately by Sage. In his process of recovering the stake, Elena shot Finn with the crossbow.
 * Stefan spent an entire evening trying to obtain the dagger from Rebekah which, at the very least kept her at bay, while Elena and Jeremy went about killing Kol.
 * On more than one occasion, Katherine has actively harmed her doppelgänger Elena. Silas made his doppelgänger, Stefan, suffer for a whole summer by stabbing him, locking him in a safe and throwing the safe off a cliff into the water under a quarry, where Stefan would drown repeatedly and die over and over for three months.
 * The very danger, of being prematurely undone by his doppelgänger, is probably why Silas locked Stefan in the safe and left him to drown repeatedly - he might have wanted to keep Stefan out of the way for as long as he remains immortal. As it turns out, Stefan's release from the safe allowed Qetsiyah to neutralise Silas' mental powers.
 * The term "Petrova Doppelgänger" comes from the last name of Katherine Petrova, the second doppelgänger of Amara. It is a term used by those who strove to find Katherine's doppelgänger and once discovered, directly referred only to Elena.
 * It is possible that the doppelgängers were finding each other and falling in love on The Other Side. Doppelgängers are known to be supernatural beings and hence, would go to The Other Side when they die. This could possibly be what Qetsiyah meant when she said she has watched versions of Silas and Amara find each other and fall in love century after century; she could have been watching them find each other and fall in love on the Other Side. However, with the destruction of the Other Side, this is presumably no longer possible.
 * Doppelgängers can be born or the doppelgänger "gene" can be passed down the bloodline without the doppelgänger himself/herself having children or a direct bloodline due to having children. For example, Silas, Amara, and Ismene; the progenitors of the Salvatore and Petrova doppelgänger bloodlines respectively, were assumed to not have had any children before they became truly immortal. Therefore, it is very likely that they had a sibling(s) which would have passed down the doppelgänger "gene" through Silas, Amara, and Ismene's respective bloodlines. So, doppelgängers would not need to have children in order for the doppelgänger "gene" to be passed down the bloodline. It should be noted that all of the known Petrova doppelgängers (i.e. Tatia and Katherine), with the exception of Elena due to becoming a vampire, have had children. It could be assumed that Silas' doppelgängers all had children as well, with the exception of Stefan, since he became a vampire and therefore, could not reproduce.
 * The two known doppelgänger lines are, both, the result of The Immortality Spell being cast. It is possible that other spells (such as The Hybrid Curse while it was active) may also produce doppelgängers depending on their nature.
 * As of Season Five, Ismene, Amara, and Silas had become mortal and died. Theoretically, being cured of immortality and their deaths means the end of their doppelgänger lines, as nature would no longer require their shadow selves to die in their places.
 * Since Tom Avery was born in the 20th century chances are is that he was meant for Elena, had she not met Stefan. If the prophecy held truth, then that means that Stefan may have never been meant to meet neither Katherine or Elena, nor fall in love with them. Katherine may have had another Salvatore doppelgänger that was meant for her, and Stefan could have had a different Petrova Doppelgänger that was meant for himself, IF, of course, the prophecy meant that two doppelgängers were born in the same century and were meant fall in love with each other.
 * It was revealed that the reason why the Travelers want the blood of the doppelgängers was because they wanted to break the curse that was placed on them by Luke and Liv's coven 2,000 years ago.
 * Qetsiyah's belief that the shadows of Silas and Amara were destined to find each other and fall in love was proven to be incorrect; it was revealed that the reason why the Salvatore and Petrova doppelgängers find each other is because of the spell that was placed on them by Markos 1,500 years earlier to obtain doppelgänger blood. The Salvatore and Petrova doppelgängers fell in love on their own throughout the centuries.
 * It was coincidental how Amara was the handmaiden of Qestiyah in 100 BC, while in the 19th century, Qestiyah's descendant Emily Bennett was the handmaiden of Amara's doppelgänger and descendant, Katherine. Another one of Qetsiyah's descendants, Bonnie Bennett, was best friends with Petrova doppelgänger Elena Gilbert, showing a pattern of Qetsiyah's descendants being involved in some way with Amara's doppelgängers. Likewise to this, Ayana was a witch, and one of Qetsiyah's descendants, that lived in the same 'New World' village as Tatia.
 * There are several theories in the show's fandom that speculate the true number of doppelgängers spawned by Amara and Silas' immortality. One theory suggests that there were nine total doppelgängers for each line, not including Silas and Amara, one for each century. This theory came from Qetsiyah's comment in Original Sin that she has been forced to watch as century after century, Silas' doppelgängers fell in love with Amara's doppelgängers and vice-versa. However, Qetsiyah could have been exaggerating or using hyperbole to describe the torture of watching their love. The second theory is that there has been one doppelgänger from each line every five hundred years, meaning that there would be Amara (1st century BC), her first doppelgänger (5th century AD), Tatia (10th century AD), Katherine (15th century AD) and Elena (20th century AD). However, since Executive Producer Julie Plec and actress Nina Dobrev had described Tatia, the Petrova doppelgänger who came between Niklaus and Elijah Mikaelson, as the first true doppelgänger after Amara became immortal, making this theory also unlikely.
 * Due to Klaus' obsession to break The Hybrid Curse over the last 1,000 years, he would have kept an eye on the Petrova Bloodline which led him to Katherine in 1492 a little over 500 years after the curse was placed on him. Then he killed her entire family after she turned herself into a vampire not knowing about Katherine's daughter, having been given away at birth two years earlier. Still he had vampires go around the world chasing after Katherine and looking for ways to break the spell for 500 years. If there had been a human Petrova Doppelgänger in the 19th Century any vampire working for Klaus would have notified him immediately. It wasn't until the 21st Century that a human Doppelgänger was found: Elena Gilbert. So not including Amara there are ONLY three known Doppelgängers in her line: Tatia, Katherine and Elena.
 * According to an interview with Michael Narducci on November 3, 2014 with ksitetv Tatia IS truly the first Doppelgänger of the Petrova Line. He explained it as such, "Tatia did have a husband prior to her relationship in the past with Elijah. He died in battle and through that marriage with the man who died she had a child. That child would begat the Petrova line and then after generations and generations, bloop, there would be another doppelgänger. And then after generations and generations there would be Elena."