Character from House of the Dragon by George R.R. Martin
The other Cargyll twin — Arryk chose the Greens, served Aegon II, and died fighting his brother Erryk in a duel that neither wanted and neither survived, the Dance's most perfect tragedy of divided loyalty.
Arryk chose the Greens because he was in King's Landing when the coup happened and because Aegon II was crowned by the proper ceremonies by the proper people, and a Kingsguard's duty is to the king who sits the throne. It was not an unreasonable position. It was also a death sentence, because his twin chose differently. He was sent to Dragonstone — or went willingly — to infiltrate the Black court using his resemblance to Erryk. Whether the mission was assassination or something else is unclear. What is clear is that the twins met, recognized each other, and fought. The duel lasted long enough that onlookers could not determine which brother was which, and when it ended, both were dead. The Cargyll twins represent the Dance's cruelest arithmetic: identical men, identical training, identical oaths, and the war made them kill each other because a kingdom could not be inherited by two people at once.
Identical to Erryk — tall, lean, dark-haired, with the same hard jaw and watchful eyes. In the white cloak of the Kingsguard he is indistinguishable from his brother, which is precisely what made the infiltration mission possible and precisely what made the duel so devastating to witness. No one watching could tell who was winning and who was losing.
Also known as: Arryk, Ser Arryk, Arryk Cargyll