Ser Arys was regarded as one of the kinder guardsmen under Joffrey. He beat Sansa when ordered by his King, but as lightly as he dared. He was also skilled with the lance, displaying absolute confidence in his ability to win a small tournament on King Joffrey's name day, despite the presence of other Kingsguard.
Ser Arys was sent to the kingdom of Dorne to guard Princess Myrcella Baratheon, who was betrothed to Prince Trystane Martell. He was seduced by Arianne Martell, daughter of Prince Doran Martell and heiress to the throne of Dorne, to rebel against the Iron Throne and support Myrcella's claim over her brother King Tommen. When the conspiracy was uncovered, Arys staged a mad charge into Martell forces and was killed by Areo Hotah, the captain of Prince Doran's guard.