Season 2 of Legion seems less interested in provoking well-informed theorizing as it is in leaving its audience in a semi-permanent state of confusion. After all, it's difficult to speculate about the future of a show when you can barely tell what's actually going on in its present. But these Future Syd Legion theories merit some analysis anyway, because something is definitely off about her.
When David was zapped into that floating orb at the end of Season 1, fans had a field day hypothesizing about who had kidnapped David and why. While a popular theory espoused that Magneto was behind the abduction, I don't think anybody predicted the real answer: that the orb contained a future version of Sydney Barrett, who told David he needed to help the Shadow King find his body, because the Shadow King would be the only one strong enough to stop another threat that had all but wiped out humanity in the future.
Ever since David so blindly accepted her insistence that he help his archnemesis — and since present-Syd so blindly accepted David's account of her own future self — some fans have been skeptical about Future Syd's true motivations… and it turns out that there are many possible explanations for her fishy behavior.
1. She's Working For The Shadow King
Syd did inhabit David's body briefly when they switched places all the way back in the Season 1 premiere. What happened while Syd was alone with the Shadow King in David's head during that time? We saw the events that unfolded from David's perspective, as Syd unleashed a psychic blast that killed Lenny and sealed everyone in their rooms at Clockworks. Could Syd and Farouk have struck some sort of bargain way back then, with Syd secretly working for the villain ever since?
2. She's Body-Swapped With The Shadow King
Then again, maybe Future Syd isn't consciously working for the Shadow King… maybe she is the Shadow King. When you have a character who can switch bodies with anyone with a touch of her finger, you have to at least consider the possibility that she's not who she appears to be at any given moment. Season 2 has been placing a lot of emphasis on Syd's body-swapping ability, showing her trading places with a cat and using her power in flashbacks to enact revenge on bullies and to experience a sexual awakening. Viewers only have Future Syd's word that Farouk is dead in her timeline; could Farouk have touched Syd in order to swap bodies with her and go back in time to trick David into helping him?
3. She's The Future Villain
When Syd appears to David in the orb, she tells him he needs to help Farouk in order to prevent an even worse villain from causing an apocalypse sometime in the future. Most theories about the identity of this villain revolve around David: that he grows unhinged after murdering Farouk and becomes an even more dangerous threat to humanity, leading Future Syd to ask David for his help in defeating… himself. But what if the villain in the future isn't David, but actually Syd? She did display some alarmingly violent tendencies in her flashback episode, brutally beating up a trio of girls who had bullied her. What if Future Syd wants David to find Farouks' body so she can swap with it and grow even more powerful?
4. She's A Vermillion
Now this is a crackpot theory if I've ever heard one… so naturally I kind of love it. What if the big bad villain in the future turns out to be not David or Syd, but Admiral Fukuyama? It's impossible to discern the true motives of the Division 3 leader, what with the basket covering his face at all times. But what if he turns into an apocalyptic threat, assimilating all of human consciousness into his hive mind and turning everyone into his android accomplices? Future Syd's voice in her interactions with David does sound suspiciously tinny, and she is always seen wearing a scarf — to strategically hide a voice box in her neck, perhaps?
5. She's Infected With A Delusion
In Jon Hamm's very first narration on the nature of delusions, the Mad Men actor recounted a parable of a man named Albert A, who became infected with the idea that his leg was not his own. So consumed by this delusion was he that he actually ended up sawing his own leg off in the bathtub one day. One of the weirdest details about Future Syd is the unexplained absence of her right arm. This could just be a random detail inserted to illustrate that things are going badly in the future… but is anything on Legion random? Given that the only other amputee on the show is Albert A, it's not unreasonable to question whether or not Syd has been infected with some sort of delusion herself. So although she may not be consciously working for the Shadow King, she may be doing his bidding unknowingly.
6. She Is A Delusion
Then again, perhaps the simplest explanation is that Future Syd doesn't really exist at all. There is still time unaccounted for during David's year-long absence from Division III; could the Shadow King have been the one who really abducted David, and then implanted the psychic with a slimy delusion to make him think an imperiled version of his lover had done it? Urging David to help him with the face of Sydney Barrett would be far easier than trying to convince him on his own. Until someone else time travels to the future to check out this apocalyptic timeline, there's no real proof that Future Syd even exists.
It may be unclear who Syd is working for or why, but it is clear that viewers should be suspicious of everything they see — especially as the season moves into its final five episodes, sure to be packed with mind-blowing twists and jaw-dropping revelations.