Sibling rivalry is one of the most common tropes in "Game of Thrones." However, House of Lannister may have the worst case in the entire realm. There have several attempts against Cersei's life, in a few of which her imp brother Tyrion was accused of being the perpetrator. In "Game of Thrones" Season 7, another sibling is rumored to plot Cersei's murder.

The last time fans saw Cersei, she has already ascended to the Iron Throne after the late King Tommen committed suicide. Cersei's rule is expected to cause a lot of chaos and blood spill, especially now that she's got nothing else to lose. As Cersei grows more of a monstrous ruler than a reasonable leader, Jamie might step in to end her reign of terror.

In "Game of Thrones" Season 5, a flashback showed Cersei meeting a seer in the forest. The seer predicted that all of her children will die. The seer then prophesied that one of Cersei's siblings will "wrap his hands around [her] pale white throat and choke the life from [her,]" The Daily Beast quoted. "Game of Thrones" theorists suggest that Jamie will be the one to take out Cersei.

Tyrion is currently busy working with Daenerys, who has named him the Hand of the Queen. Although he probably still harbors a lot of hate for his sister, he's probably too preoccupied to attend to personal vengeance. Meanwhile, Jamie is the closest to Cersei at this point. Jamie is all the family Cersei has left, and is probably the only person that can get close to her.

Moreover, after learning that Cersei had ignited the wildfire that killed hundreds of people in King's Landing, actor Nickolaj Coster-Waldau revealed that Jamie is in shock. After all, Jamie killed Mad King Aerys to stop him from setting the wildfire and exploding half of King's Landing.

"The woman you love has turned into this seemingly mad woman. If you were a couples counselor, you would tell him to maybe reconsider this relationship," Waldau said in a New York Times interview. "On a scale of 1 to 100, with 100 being this is the moment when you have to leave, I think we are at 99.9."

At this point, fans believe that Jamie has probably had enough of Cersei's evil workings and that he probably blames her for Tommen's suicide, since it was the wildfire that killed Tommen's wife Queen Margaery.

Actress Lena Headey, who plays Cersei, also hinted that Cersei will rule for a long time and that she would die at the hands of the "right person."

"Game of Thrones" Season 7 returns to HBO in 2017.