Game Of Thrones: 10 Theories On Who Will Kill Cersei Lannister

7. Brienne Of Tarth

Brienne was the younger sister to Galladon Tarth - who died as an 8-year-old (she also had two sisters who died as babies) - so she fits the bill as a younger sibling. Brienne and Cersei haven't had too much to do with each other, but their brief meetings have shown they aren't exactly gonna be gal-pals anytime soon. Similarly, in terms of the younger, more beautiful person who could cast her down, Brienne is younger and was called Brienne the Beauty (albeit mockingly) so there is that aspect to consider as well. Most likely, if this were to happen, it'd have something to do with Jaime. He and Brienne are very close, and depending on how that relationship continues to develop could even be considered as taking the thing that Cersei holds dear. It's a bit of a more 'out-there' idea, but would be rather awesome.