O' Reilly is a foul mouthed brute who tries to keep in order over his subordinate raiders. He is your typical raider captain. He is adept in the fine arts of torture, tactics, strategy, and belching and guzzling beer. He doesn't have much to play in the story except for a few choice one-liners. He does get to shout them out very loudly, if that's any consolation to him.