In the Season 6 finale of Game of Thrones, Arya finally made her way back to Westeros and got her revenge on the Freys. Using what she's learned on her travels and from her time with the Faceless Men, Arya disguised herself as one of the Freys' servants and cut up Walder Frey's son, baked them into bread, and served it to him. She then slit his throat the same way her mother's was slit. How's that for sweet revenge? Now that Arya's list of people to kill has gotten significantly smaller, fans can't help but wonder if Arya will be the one to kill Cersei.
With so many tools and skills now under her belt, Arya definitely has the means to kill Cersei and with Cersei now acting as the "Mad Queen" it would be in everyone's best interest if Arya killed her. But how exactly would Arya kill Cersei?
Arya has definitely become a skilled assassin, but getting to Cersei won't be easy, especially now that Cersei is a bit crazier than she was before the Season 6 finale. Although Cersei got rid of most of her enemies by blowing up the Great Sept, she knows full well there are many others out there that will come for the Iron Throne. As the finale proved, Cersei will do anything to keep her power and Arya will have to find a way to work around that.
One fan theory seems to provide an answer to that. Although we don't see it in the show, there's another piece to the prophecy Maggy the Frog gave to a young Cersei.
“When your tears have drowned you, the Valonqar shall wrap his hands about your pale white throat and choke the life from you," Maggy told Cersei in A Feast of Crows. Valonqar means "little brother" in High Valyrian, which Cersei has always interpreted to mean that Tyrion will kill her, however many fans believe it will actually be Jaime who does the deed. But how does Arya come into play? Well, one theory suggests that Arya will somehow sneak her way into King's Landing and kill Jaime. She will then take his face, using it to trick Cersei, and then kill her, thereby fulfilling the prophecy (sort of).
Although it sounds crazy, almost everything on Game of Thrones is crazy. And as we've already seen Arya has no problem using the skills of the Faceless Men to get her vengeance. Even though Jaime isn't on her list it's doubtful Arya would feel any remorse in killing him to get to Cersei, especially because he's a Lannister.
Unfortunately, we have a long way to go to see if this theory will pan out. Whether it's Arya or someone else coming for Cersei, she should probably watch her back.