When asking some avid Game of Thrones fans why they disliked the controversial series finale, one recurring point will be that an important part of Cersei’s prophecy was cut, which completely changed her fate. Aside from her vile son Joffrey and the psychopathic Ramsay, Cersei was one of the most significant villains throughout Game of Thrones—one that fans couldn’t wait to see meet an ugly end in the last episode. While she did die in the end, it was largely underwhelming, with Cersei and Jaime being crushed alive as the Red Keep collapsed on top of them.
Much of the anticipation for Cersei’s eventual Game of Thrones demise came from the prophecy introduced in both the A Song of Ice and Fire novels and season 5 of the show, where a young Cersei wanders into the woods of Casterly Rock and forces a witch to relate her future. In Game of Thrones, Maggy the Frog tells Cersei she’ll be the queen before another takes her place and casts down all she holds dear and she’ll have three children with gold hair who will all perish. Maggy the Frog’s Game of Thrones predictions all came true, but it was missing one key aspect of the novel’s original prophecy that would have changed Cersei's fate.
In the novel, Maggy the Frog ends Cersei’s prophecy by saying, “the valonqar shall wrap his hands about your pale white throat and choke the life from you.” It’s a pretty significant aspect of Cersei’s future that was erased from the show, especially since it hinted at who would be the character to kill her. In High Valyrian, valonqar translates to “little brother,” which means both Tyrion and Jaime are fair game since Cersei was born slightly before her twin brother. In reference to character resolution, Cersei being killed by Jaime was theorized about more than any other demise, which makes it all the more curious why Game of Thrones’ writers cut this important detail. When looking back after Game of Thrones’ season 8 finale, it seems it was left out in season 5 because the writers never actually intended for her to die by her brother's hand.
Many argued that Jaime should have been the one to kill Cersei because it would have completed his character arc, going from a selfish man pining for his sister to a thoughtful, selfless hero who betrayed her to fight in the Battle of Winterfell and fell for the highly revered Brienne of Tarth. It was widely speculated that Jaime would go into the Red Keep to kill Queen Cersei and protect the realm, just as he had with the Mad King a few decades earlier, but in the end, he reverted back to his loyalty to Cersei like a drug he just couldn’t quit. Tyrion also wasn’t going to kill Cersei because she was pregnant, and he knew that Cersei could possibly redeem herself because of how devoted she was to selflessly protecting her children. Tyrion has much more sympathy for Cersei in Game of Thrones than in the books, so it tracks that they cut the prophecy to alleviate the idea that Tyrion would kill his own sister who even though undeserved, he still loved.
Even though the valonqar aspect of Cersei’s prophecy was cut in the season 5 flashback scene, many still held hope that it would make its way back into the series finale. It’s possible that writers hadn’t vetoed the idea and could have worked it in, and just found that it would need to be drawn out far more and they didn’t have the time. One common critique of Game of Thrones’ finale is that the storylines were far too rushed, which could possibly be why the valonqar prophecy never came to fruition. Additionally, they may have felt it repetitive to show Jon Snow betraying Daenerys by murdering her right after showing Jaime come to the same realization about having to betray and kill Cersei. The Jon-Daenerys resolution was more significant to the series’ culmination, so Game of Thrones likely chose to include that family/lover betrayal over Cersei and Jaime’s.