After literally burning her enemies to the ground, as she always promised she would, and taking the Iron Throne for herself, Cersei seems to have won on Game of Thrones, after Season 6's explosive (literally) finale. But nobody, not even actress Lena Headey who plays Cersei, thinks she'll last long. She even has some theories herself on who will be the one to finally take Cersei down. Since Maggy the Frog's first prophecy, that she would watch all three of her children die, came to be totally true, now we're left wondering how the second part of the prophecy, that Cersei herself will be killed by a "little brother" will come to be. Will Tyrion kill Cersei on Game of Thrones?
It's definitely possible that Tyrion will be the one to take Cersei down after her ascent. In an interview with Entertainment Weekly, Headey was asked if she thought that Cersei was long for the Iron Throne, and her response was "No, surely not." She then said that the person who should kill Cersei should be either Arya or Tyrion. We know that Tyrion is on his way back to King's Landing with Danaerys and her army. If he does end up the one to kill Cersei, it would be immensely satisfying, and not just to him.
Tyrion and Cersei have never exactly gotten along. Certainly not the way Cersei and Jaime got along (shudder). In fact, Cersei still believes it was Tyrion who poisoned Joffrey and is likely to try to execute him as soon as he steps foot in King's Landing. For his part, Tyrion once issued this beautifully worded threat to his sister, after she kills a prostitute, thinking it was Tyrion's Shae,
I will hurt you for this. A day will come when you think you are safe and happy, and your joy will turn to ashes in your mouth. And you will know the debt is paid.
Sitting on the Iron Throne as Queen with almost all of her known enemies dead, Cersei almost certainly believes herself to be totally safe. This could be the moment that Tyrion's prophetic words come true. The "little brother" prophecy could mean Jaime, who it has been established was born slightly after Cersei, or it could even mean Arya, who is a "little sibling" (gender pronouns in Valyrian are known to be rather fluid). But perhaps the most poetic candidate to finally end Cersei would be the brother she simultaneously despised, respected, even feared, Tyrion.