Legends of Tomorrow began with Rip Hunter (Arthur Darvill) assembling a group of eight "Legends" to do battle with his enemy Vandal Savage. Serving on his team were Sara (Caity Lotz), Ray (Brandon Routh) Firestorm (Victor Garber and Franz Drameh), Carter (Falk Hentschel), Kendra (Ciara Renee), Rory (Dominic Purcell), and Snart (Wentworth Miller.) At the end of season 1, Snart was killed, and Kendra and Carter parted ways with the Legends. In season 2, the characters were replaced by Nate (Nick Zano) and Amaya (Maisie Richardson-Sellers). With Rip no longer a member of the crew and Garber set to leave the series, the Legends may be in need of fresh blood.
In a conversation with EW, Ashe discussed the role of Zari on Legends of Tomorrow and revealed that the character will be reluctant to join the team:
She’s not an obvious choice to join the Legends, and to be part of a team. In the early episodes, you’re going to see that she’s fighting the narrative of being a superhero, but also being part of a team and trusting people because I think that’s something that has burned her in the past. Because of her upbringing, it’s not something that she easily adheres to. She is brilliant in that sense and says what’s on her mind, and it’s a different tone to bring to the group of Legends. She shakes them up and challenges their mission.
Based on earlier comments, it could be that Zari's biggest problem with working with the Legends is the mission itself: to fix history. As a hacktivist from a bleak, dystopian future, Zari may be more interested in improving history than simply fixing it back to the way it was. This would clearly violate the rules of time travel and bring her into conflict not only with her teammates but with Rip Hunter's Time Bureau. It's been stated before that Zari's views will have an effect on the Legends, particularly Ray. Routh said during SDCC that Zari would force Ray to wonder if he should be doing more to change the world with his technology.
Zari, based on the comic book character Isis, will debut on the third episode of Legends of Tomorrow, titled "Zari."
Legends of Tomorrow airs Tuesdays @9pm on The CW.