Elle is introduced in the episode "Fight or Flight" as an agent of the Company, an organization whose primary purpose is to identify, monitor and study those individuals with special genetically derived special abilities. The daughter of Company head Robert Bishop, she possesses the power to generate and manipulate electricity. Elle is shown to be mentally unstable, which is attributed to extensive testing condoned by her father to research her abilities when she was young.
The character Elle was created long before Bell was cast; however, Kring noted "when you do cast an actor ... you try to tailor that character a little closer to who the actor is. So it's hard to know when one starts to influence the other".
Elle next appears in "Four Months Ago...". During this time, the Company made Peter their willing prisoner and in those months he was held, Elle seems to have developed a crush on him, later Peter confesses that he likes the little jolts which Elle gives him as a tease and kisses her. She confides in Peter that she has lived in the Company's holding facility for sixteen years. She also admits to being diagnosed as a sociopath; she explains at age six, she accidentally set her grandmother's house on fire and at age eight, caused a major blackout in Ohio. When he escapes from the facility, Elle is upset and angry to the point that she blasts him, setting him ablaze during his escape.
In "Cautionary Tales", Elle came back to the United States. Former Company employee Noah Bennet, captures Elle for collateral as Bob had managed to capture his daughter. He ties her hands to a chair and ties her bare feet together and puts them in a dogbath. Elle tries to use her abilities while in the dogbath, but she shocks herself. During this time, Noah tells Elle that Bob allowed the Company to perform tests on her which had begun as early as the age of seven. This included subjecting her to high doses of electricity, which led to her twisted personality. Elle has no recollection of the tests, and Noah suggests the Haitian had a role in causing Elle to forget her experiences. After an agreement is made, she is reunited with Bob and Claire momentarily reunited with Noah. However, Elle attacks Claire and West as they leave. She tries to attack Noah, but he shoots Elle in the arm before she can hurt him or anyone else. As it seems Noah is going to kill Bob, Mohinder Suresh, a scientist working with Noah and the Company, shoots and kills Noah. She leaves with Bob and Mohinder, giving Bob a look of distrust.
In the episode "Truth & Consequences", Bob chastises Elle for allowing West and Claire to escape. He then assigns Elle to perform surveillance on Claire and her family as they prepare to leave town. Claire, however, spots Elle from a distance, leading to a physical confrontation.
Elle's last appearance in season two is in "Powerless". She is reprimanded by her father for her mistakes, and to redeem herself, she attempts to re-capture the now powerless Sylar for the Company. She uses her ability to confront Sylar in Mohinder's research lab, but Sylar is armed with a gun and shoots at Elle. Sylar manages to slip away, leaving Elle unharmed. She comes out somewhat defeated, but is informed by Mohinder that if not for her arrival, Sylar would have killed him, Maya and Molly. He says the three of them owe her their lives, to which she replies, "Cool".
The episode marked Bell's previously expressed interest in performing in scenes with the character Sylar, as she and Zachary Quinto have been good friends for almost ten years. Bell had said that she "would love to see him and Elle face off one day". In November 2007, Bell and Quinto filmed scenes at a restaurant in Los Angeles, which was set as a "New Jersey Diner" and had involved police and paramedics. The filmed scenes have yet to be used on an episode.
In "The Butterfly Effect," after discovering that her father has been murdered by Sylar, Elle goes to Level 5, a high security ward for the most notorious prisoners of the Company, to attain assistance from Noah Bennet. However, Sylar is already there, and attempts to take her ability. When he begins cutting into her head, however, she releases a huge blast of electricity. Sylar is knocked out, but the blast also shuts down the power to the prison cells, releasing the prisoners. Elle is later fired by Angela Petrelli - the new head of the Company - who tells Elle that the only reason the Company kept her was because of her father's insistance.
Bell has said in interviews that in later episodes of Heroes, "You'll find out that Elle holds the key to Claire's future" and that Elle has "a [present] with Peter and a past with Claire's dad and a future with Claire".
Kristen Bell has five episodes left on her Heroes guest star contract.
Elle has the ability to generate and manipulate electricity, discharging and directing it as electrical arcs. She has been shown being able to weld a lock, blast objects, knock people unconscious, and even kill a man. She is not entirely immune to the electricity she produces, however, as shown when she is drenched in water and attempts to create electricity — she gives herself an electric shock, causing great pain. Elle has endured a series of testing by the Company during her childhood that measured the extent of her power. Bob had stated that Elle was in a "different league" when comparing her to Claire. When inquiring about her abilities, Elle was able to learn from Noah Bennet that the Company had wanted to record the extent of her abilities (whether she could power a flashlight, a street lamp, or an entire city block) and Bob had often prompted to continue the tests further, even after Elle had passed out.
During an interview with thescifiworld.net, Tim Kring described Elle as "a little off", and Bell added that Elle is "a little messed up in the head" and a highly conflicted individual who does not have the ability to decipher between right and wrong. Because of that, Bell explains that Elle comes off as more of a victim. Bell also explains that Elle is one of the few characters with abilities that embrace their power and is almost on the verge of being addicted to her ability. Elle "enjoys the emotional power it gives her over other people" which causes her to be manipulative. She is described as one who is "always out to get what she wants" and someone who "doesn’t have many boundaries". Bell describes Elle as a vixen who "feels like she has a romantic connection to everybody", and in a few episodes, Elle is shown displaying a great deal of affection to men and flirting with both Peter Petrelli and Mohinder Suresh.
Bell noted the similarities between Elle and the character Claire Bennet, saying that they "relate to each other" and "are two sides of the same coin" because, while Elle's father sanctioned testing on her, supposedly causing her mental instability, Noah kept Claire hidden, preventing Claire from experiencing the same childhood that "really messed [Elle] up".
In an interview with Bell, Eric Goldman of IGN, commented on the Bell's "eagerly awaited debut" on the series. Matt Roush of TV Guide reported on Bell becoming a series regular on Heroes, and stated he "like[s] her more and more, especially as we see the tragic dimension of how Elle has been so cruelly used by her 'daddy,' Bob, and is much more than the flirty assassin we first met. Bruce Fretts, also of TV Guide, said that Bell's portrayal of Elle was responsible for "sparking Heroes to life." He explains that "[i]n just a few scenes... [Bell is able to] juice up the slumping sophomore drama" and her "live-wire performance turned Chapter 5 into this season's strongest episode yet." However, because of the large ensemble cast, Matthew Gilbert of Slate.com commented that season two of Heroes was "even more overpopulated than the last, expanding from a rabble to a veritable global riot of Dubiously Gifted Ones.