The second episode of Game of Thrones' eighth season paid fan service to a bunch of different characters, many of whom may not make it out of the Battle of Winterfell alive. One particularly standout moment was Arya and Gendry having sex, knowing full well this could be their last night on Earth. But as they were taking off their clothes, Gendry (and fans) noticed several scars on Arya's body. So how did Arya get her scars on Game of Thrones? The moment has called to mind a popular fan theory that's been circulating for quite some time.
At the end of Season 6, Arya and the Waif had their final showdown in Braavos. After failing to carry out the assassination of Lady Crane, the Waif stabbed Arya multiple times in the stomach before falling into the water and presumed dead. Thankfully, Lady Crane was able to help treat Arya's wounds, but that didn't stop the Waif from returning to finish the job. She killed Lady Crane and chased after Arya, who led her down a dark alley and was able to finish the Waif off for good — or so we were led to believe.
Based on this information, the most logical conclusion is that Arya's scars are from her brutal encounters with the Waif. But some fans may recall that Arya's stabbings were located on her stomach, not on the sides like we saw on Sunday night, which means she's developed other scars we have yet to learn about or it helps prove the theory that Arya is actually the Waif in disguise.
They theory suggests that the Waif did actually kill Arya in Braavos and she's been wearing her face ever since. However, it's important to remember that there are a few significant holes in this potential plot twist. For one, how would the Waif know Hot Pie when Arya encountered him in Season 7?
Same goes for when she recognized Nymeria in the woods and her former direwolf prevented her pack from attacking. Wouldn't the animal have known it wasn't really her? Plus, it seems doubtful the Waif came to know that much about Arya's past. (Maybe she would've mentioned Nymeria, but Hot Pie feels like a stretch.)
That's why Reddit users like catNamedStupidity have taken this theory to the next level and suggested that Arya and the Waif are actually the same person, with the Waif only serving as a figment of Arya's imagination. That's why no one blinked an eye when Arya was getting beaten up by the Waif in the street or why no one other than Jaqen H’ghar and Arya seemed to know of her existence. It definitely makes a lot of sense and would explain why the Waif's "death" coincided so nicely with Arya reclaiming her identity as a Stark and wanting to go home.
As for the location of Arya's scars and why they don't seem to match the location of her stab wounds, these could be a product of a different encounter we have yet to know about. Or maybe the Waif hurt her more extensively than we ever realized, or it was a product of one of their grueling training sessions.
Either way, it was more than likely meant to show Gendry that she's no longer the young girl he once knew. She's a woman who has clearly been through some stuff and isn't afraid to go after what she wants, whether that be in the battlefield or in the bedroom.