Warning: SPOILERS for DC's Legends of Tomorrow's season 5 finale - "Swan Thong"
Sara Lance (Caity Lotz) lost her superpower in DC's Legends of Tomorrow's season 5 finale and she can never get it back because the source of her power is gone. Legends of Tomorrow season 5 saw the time-traveling misfit superheroes fighting the Fates of Greek myths, who used the mystical Loom of Fate to rewrite history and subjugate humanity into their dystopian idea of perfect order. In a twist, Sara magically gained a superpower after she survived an encounter with one of the Fates, Atropos (Joanna Vanderham), in episode 9, "Zari, Not Zari." The finale saw the Legends defeat the fates — and Sara lost her newly-acquired powers in the process.
Even among the Arrowverse's greatest heroes like Supergirl (Melissa Benoist), the Flash (Grant Gustin), and Green Arrow (Oliver Queen), Sara Lance, a.k.a White Canary, is special. This was verified during Crisis on Infinite Earths, when Sara was named the Paragon of Destiny, playing a key role in the defeat of the Anti-Monitor. After the Crisis, Sara became a founding member of Earth-Prime's Justice League. But Sara's top priority is the Legends, who are her makeshift family, and her girlfriend Ava Sharpe (Jes Macallan). In Legends of Tomorrow season 5, Sara considered a job offer by Rene Ramirez, a.k.a. Wild Dog (Rick Gonzalez), to help him run Star City; however, her heart belongs to the Legends, so she returned to the Waverider to continue her role as the team's Co-Captain alongside Ava.
As a former member of the League of Assassins, White Canary is one of the Arrowverse's most dangerous fighters, and she never needed superpowers to be a hero. However, in Legends of Tomorrow season 5, Sara unexpectedly gained an ability when she survived an encounter with Atropos, who is one of the three Fates along with her sisters Lachesis (Sara Strange) and Clotho a.k.a. Charlie (Maisie Richardson-Sellers), a shapeshifter who joined the Legends in season 4. When Sara saw Atropos' true godlike form, she gained the power of clairvoyance, which mainly manifested as the ability to see how she and anyone who touches her will die. But Sara's precognition came with a catch — it left her blind. Thankfully, Ava helped run the Legends while Sara coped with her disability, although being blind didn't slow White Canary down, and she was still able to fight and accomplish feats like defeat Hudson University's party king, the Greek god Dionysis (Drew Ray Tanner), at beer pong.
Sara gaining clairvoyance from Atropos was fitting because it essentially made her like Cassandra of Greek myths, who was a priestess of Apollo cursed to utter true prophecies. Atropos herself was a malevolent Greek god; known as "the thread cutter," her task was to end the lives of humans in accordance with the Loom of Fate. Atropos was an unstoppable warrior — until she met Sara Lance.
In Legends of Tomorrow's season 5 finale, "Swan Thong," Sara battled Atropos for the last time and the true purpose of her precognition was revealed: Sara saw how Atropos planned to kill her and she was able to catch her blade. Captain Lance then realized the Loom of Fate could kill Atropos so she trapped the god in the device and pulled Atropos' own thread. Atropos was destroyed along with the Loom, but as a result, Sara lost her superpower and regained her eyesight. Since Sara's clairvoyance was directly linked to Atropos, the Fate's death took Lance's power away. Because it's doubtful Atropos will return to plague the Legends, Sara's precognition is gone for good. Not that this concerned Sara in the slightest since she's happy to be back to normal.
In truth, Sara Lance has no need of superhuman abilities, and she's an incredible hero exactly as she is. As a one-time circumstance, though, Sara having powers was a well-conceived plot development that helped the Legends overcome their powerful season 5 Big Bads. But ironically, if Sara still had her clairvoyance, she might have foreseen that she was about to be abducted by aliens in the final moments of Legends of Tomorrow's season 5 finale.