Since the show's inception, fans have been wondering how Cersei Lannister will die on Game of Thrones. Her fate feels like it's been written — because it has. In the books, Cersei visited a witch who predicted her future. Part of the witch's prophecy was that she would die at the hands of the "valonqar" — which is High Valyrian for "little brother." But that exact prophecy didn't make it into the show, which leaves her likely death up for debate. Of course, she could survive the war — but for the sake of argument, let's assume she does die, and at the hands of another character, because there are quite a few theories about who will kill Cersei in the end.
GoT fans are a clever bunch, so there's probably a compelling theory out there for just about any character killing Cersei. Some are a bit more far-fetched than others, and as much as I would love if one of those elephants Cersei won't shut up about showed up and trampled her, let's talk about the most compelling theories. They all have something to do with two key parts of the prophecy — the younger queen and the little brother.
In both the book and the show, the witch predicts that "another, younger, more beautiful [queen will] cast [Cersei] down and take all [she] holds dear." And in the book, the witch adds one more section to the prophecy that isn't stated in the show.
"And when your tears have drowned you, the valonqar shall wrap his hands about your pale white throat and choke the life from you."
With the prophecy in mind, here are eight plausible people who could kill Cersei.
Because Dany wants the Iron Throne that Cersei currently occupies, Dany is the obvious choice. She's also has dragons at her side that she loves using to flambé people, so death by Dany's dragon is a real possibility for Cersei in the next few episodes. The "little brother" part of the prophecy could mean that her dragon Rhaegal will kill Cersei. Rhaegal is the little brother to the much larger Drogon. That would fulfill both parts of the prophecy in the book.
Technically Sansa is not a queen, but she really should be Queen in the North, already. And she has a real beef with Cersei for ruining huge parts of her life. Sansa got to kill Ramsay, which was hugely cathartic for her, and killing Cersei would be much the same.
Jaime hasn't been pleased with Cersei's actions since she lied about aiding in the war against the White Walkers. He actually left her to go fight for Jon Snow, so he may reach a breaking point and be the little brother who kills her.
Another popular theory is that Arya wears Jaime's face to kill Cersei, fulfilling the valonqar prophecy while also allowing Arya to cross a name off her list. And many fans believe that Melisandre hinted to Arya that she would kill Cersei in the last episode. Melisandre told Arya that she would shut many eyes forever, including brown eyes, blue eyes, and green eyes. Astute fans pointed out that Walder Frey (who Arya has already killed) had brown eyes, the Night King had blue eyes, and... Cersei has green eyes.
While Jaime is the favorite little brother to kill Cersei, it mustn't be ignored that Tyrion is also her little brother. And after she lied to him about sending the Lannister army to aid in the White Walker fight, he's not too happy to have been played a fool. If he also finds out that Cersei's ordered a hit on his head, he may well strike first.
He's The Mountain's little brother, and The Mountain is Cersei's bodyguard. Perhaps The Hound kills them both in a Cleganebowl situation?
Her Unborn Child
If Cersei is still pregnant (TBD on that), some fans think the child will be a boy and he will kill her in childbirth or in a miscarriage. The witch's prophecy said that Cersei was only going to have three children, and that they'd all die. That part of the prophecy has been fulfilled with Joffrey, Myrcella, and Tommen. She shouldn't be able to have another child by the prophecy's definition, which is why many fans think this pregnancy will be her undoing.
Cersei could survive the next three episodes, but it's unlikely. So all fans have to wait for is to see which of these theories is right in the end.