<P> Much of Elena's story revolves around her relationships with vampires Stefan Salvatore and his older brother, Damon . It is revealed that Elena is a Petrova Doppelgänger, which is thus responsible for her being identical to her ancestor, Katherine Pierce (née Katerina Petrova). This also has the implication of making her a supernatural creature . Dobrev portrayed the "conniving" Katherine as well, who is opposite of Elena . The actress stated that it has been a challenge distinguishing the two, and enjoys playing them both . In the television series's fourth season, Elena becomes a vampire and deals with the struggles that come with her change . She took the cure and became human again towards the end of the sixth season . In the finale of the sixth season, Kai linked Elena to Bonnie's life by magic . Elena will only wake up when Bonnie dies in around 60 years . She was locked inside the Salvatore tomb, then relocated to a warehouse in Brooklyn, New York in the seventh season, then back to Mystic Falls . In late 2016, when it was announced that the eighth season would be the final season, Dobrev was in talks about returning to the television series to reprise her role in the final episode . After much speculation . Dobrev's return was confirmed on January 26, 2017, via an Instagram post . Dobrev appeared in the final episode of the show as both Elena and her evil doppelgänger Katherine Pierce . </P> <P> On March 9, 2009, it was announced that Bulgarian - born Canadian actress Nina Dobrev, known for her portrayal of Mia Jones on Degrassi: The Next Generation, had joined the cast of The Vampire Diaries as Elena . She was the second cast member to be announced following Steven R. McQueen, who plays Elena's brother Jeremy Gilbert . Steve West Cinema Blend said the vampire brothers' battle over Elena will wreak havoc on the entire town. ". Executive producer Kevin Williamson recalled Dobrev auditioning while having the flu, which he described as the "worst audition ever", and they "didn't even look at her a second time". Dobrev went back home to Canada, yet, still wanting the part, she submitted a videotape audition, which saw her cast as Elena Gilbert . </P> <P> Dobrev said that after reading the script, she was drawn to Elena because she was "this average girl who was damaged in many ways". Initially, she believed that she would be playing the "bad girl" Elena from the books, but the show wanted to go in a different direction for the character . After researching, Dobrev discovered she would also play Elena's 534 - year - old vampire doppelgänger Katherine Pierce whose characteristics are the "complete opposite". Dobrev described this as "one of the rarest, coolest opportunities in television, to play two people on the same medium". She had confessed that she enjoys playing Katherine more than Elena . Dobrev stated that she changes her appearance to distinguish Elena from her doppelgänger, Katherine; "Changing my hair helps me transform," she told Glamour . Additionally, she said "I think I have one of the coolest characters on the show--I get to play two completely different people on opposite sides of the spectrum and I just have so much fun doing it". Dobrev felt that her biggest challenge on The Vampire Diaries was distinguishing Katherine and Elena, and found it "interesting" to create a whole new character . In the novels, Katherine originated from Germany . However, in the television series, she is Bulgarian, as is Dobrev, who can speak the language fluently . Dobrev said, "The writers heard me speaking Bulgarian to my mom on the phone while I was on set one day . One thing led to the other and voila". </P> <P> In the books, Elena is considered "one of the popular girls" at her high school and always gets "anything she wants". Executive producer of the television show, Julie Plec, said the Elena from the books was "really kind of selfish". In The Vampire Diaries, Elena's "selfishness" in the books as a human was never explored, because it "didn't ever feel like a characteristic" the show wanted for their heroine . Plec said "We kind of abandoned that queen - bee popular complex that in a lot of ways defined early Elena in the books", while feeling that Elena's actual flaw is her "deep, deep connection to other people". In the books, Elena had blonde hair, but has brown hair in the television show . Describing Elena from the books, Dobrev said she is "one of those mean girls that gets what she wants, popular...and she's blonde and blue eyed". Williamson told her that "the angle we wanted to go for was the relatable, nice, girl next door, who the audience roots for". Katherine, on the other hand, is penned as a "conniving, narcissistic, bitch". Describing Elena years later, Dobrev said she evolved from a "younger, naive, sad, young girl" to a "strong woman". </P>

What episode does elena turn into a vampire on vampire diaries