<P> Tywin and the Westermen regroup at Harrenhal, with Tywin taking Arya Stark as his cupbearer, whom he treats with respect although he is unaware of her true identity . When Stannis Baratheon sails on King's Landing, Tywin leads his forces and their new allies of House Tyrell on the city and arrives in time to defeat Stannis' remaining forces . After the battle, Tywin is named "Savior of the City". </P> <P> Tywin furiously denies Tyrion his request to be named as heir to Casterly Rock, but does acquiesce to naming him Master of Coin . When he learns of Olenna Tyrell's plot to have Loras Tyrell wed Sansa Stark, he arranges to have Tyrion and Cersei marry Sansa and Loras respectively . He also allies with Robb Stark's dissatisfied bannermen, Walder Frey and Roose Bolton, conspiring with them to have Robb Stark assassinated at the Red Wedding . </P> <P> Tywin has the Stark ancestral sword Ice melted down into two swords, one of which he gives to Jaime, though he disowns him after Jaime refuses to resign from the Kingsguard to become Tywin's heir . When Tyrion is accused of poisoning Joffrey, Tywin asks Prince Oberyn Martell to serve as one of the judges in Tyrion's trial . Though Oberyn despises Tywin for ordering the death of his sister, niece and nephew during the sack of King's Landing, he agrees when Tywin offers him justice against their murderer, Ser Gregor Clegane . Tywin also presses Cersei to wed Loras in order to use House Tyrell's wealth to pay off the Crown's debts to the Iron Bank of Braavos, but is forced to back down when Cersei threatens to reveal her incestuous affair with Jaime . Tywin has an affair with the prostitute Shae, formerly Tyrion's mistress . Tyrion discovers this during his escape from King's Landing and strangles Shae before confronting Tywin on the privy . When Tyrion admits that he loved Shae, Tywin repeatedly dismisses her as a whore, prompting Tyrion to shoot him with a crossbow, killing him . </P> <P> Tywin's body lies in state in the Great Sept of Baelor before his burial, with Jaime and Cersei the first to pay their respects . Tywin's death greatly destabilises King's Landing, namely by allowing the rise to power of the High Sparrow and the Faith Militant . </P>

Who kills tywin lannister in game of thrones