the fighter watchman is located at the arena in Port Kapul and guards the staircase leading down into the Fighters Guild. You may ask him about the Fighters Guild and may also request to join, which requires that you hunt and kill several (up to fifteen) monsters of randomly chosen type. After joining, he also advances your guild rank, which is done through similar, but increasingly difficult hunts. If you enter the Fighters Guild by teleporting Doria away, killing him or through him being assassinated, you will be attacked by the guild members within.