Kieran was a soldier of the Crimean Army before Daein invaded and occupied Crimea. He, Brom, and Nepheenee were all captured as prisoners of war and locked up in a dungeon. Ike and his Mercenary band rescued them and let them join the Greil Mercenaries to safely escort Princess Elincia to Gallia and free Crimea. Kieran claims to be Oscar's rival but they work it out and become friends in the end.