u/Goldsaver

Consider famous scenes where a villainous character is about to kill, maim, or otherwise seriously harm an innocent person, only this time a drunk Westerosi knight bursts through the nearest door, screams "In the name of the Mother, leave that (relevant noun) be," pukes, then starts swinging with surprising skill. What are some major tragic murders or other incidents where the sudden presence of a knight who remembers his vows could turn the tide?

For some examples: Ser Arlan probably gets fried by Ozai before burning Zuko, but I bet he could decapitate a very startled Shou Tucker before he merges Nina and Alexander.