Shauna and Jackie
No one haunts the narrative like Jackie Taylor. For as much as some may have wanted to be rid of her, if there is any late character who is never being let go of, it is the former captain of the soccer team. Even dead, Shauna is unable to truly get rid of her in either timeline. For 1997's iteration of Shauna, Jackie still remains a figure of love, loss, hurt, comfort, and tragedy. Shauna and Jackie never got the opportunity to reconcile from their explosive fight, and thus, Shauna is still grieving her best friend and their relationship that never got to heal. However, things do not get better as an adult, as Shauna still continues to hallucinate Jackie.
Yellowjackets continues to thread the needle of Shauna's struggle to handle being jealous of Jackie and potentially wanting to be with Jackie. As an adult, Jackie taunts Shauna with the idea that Jackie is still the most interesting thing about Shauna and that all these years later, even with Jackie dead, Shauna was never able to escape Jackie's shadow, instead stepping right into it. Shauna married Jackie's high school boyfriend, potentially because he was familiar and the closest thing Shauna still had to her late best friend. Shauna's feelings toward Jackie are complicated, perhaps the most complicated in the series, given the lack of closure. In season three, Jackie haunts Shauna in both timelines, as Shauna continues to not fully admit or embrace exactly why she is unable to let Jackie go.
Of every character who has died on Yellowjackets so far, Jackie haunts the narrative the most. Jackie was the team captain, something Natalie was quick to reference when Hannah was trying to determine which of them was in charge. Without Jackie there to bring the team together, as was originally one of her biggest talents established in the first season, the group has been breaking apart, but latched together by their shared trauma and growing sense of chaos and animalistic desires. As it turns out, as much as Shauna may have questioned who she would be without being in Jackie's shadow, the answer may not be one she predicted. Meanwhile, as an adult, Shauna still can not help herself from seeing Jackie everywhere, including potentially in her own daughter, as Callie may remind Shauna more of Jackie than of herself.
Whether it be in her choice of husband, having continued a relationship with Jackie's parents, or her constant Jackie-filled hallucinations and conversations with a ghost, there has been no way for Shauna to escape the hold that Jackie has on her so many years later. Jackie Taylor died before things got truly bad for the group, and remained one of the only members who never got to experience or know the horrors of what occurred once winter hit, or never knew just how close the group could have come to rescue. Jackie's presence on the show remains strong even when she is not present. No matter what timeline it is, Shauna Shipman will never outrun Jackie Taylor.