"Oh no, there's just one, but it has two kings!" Eilonwy explained. "They're always fighting, and this ties into things. Before Pwyll and Arawn traded places, Arawn told Pwyll that if Hafgan ever challenged him to a fight then he would need to make sure to end it with precisely one strike. No more, no less. Pwyll remembered this as Hafgan again challenged him to a fight, offended that Arawn had left in the first place. Pwyll accepted and prepared himself."