With Robert Baratheon and Ned Stark dead, and her son seated on the Iron Throne, Cersei Lannister now has a ruling hand in the Seven Kingdoms. Though Catelyn Stark has her twin/lover Jaime as a hostage, Cersei has the scale balanced by claiming Sansa and Arya Stark as hostages (though she doesn't actually have Ayra).

With her power consolidated, Cersei will soon learn - as Robert did - that there is a big difference between winning a throne and keeping it. And when Tyrion arrives to manage the kingdom in her stead, Cersei will not take the insult lightly.

everything we learned from the prey trailer
Prey’s Warrior Face Paint Has a Deeper Meaning Than Predator Fans Realize