Dunban first appears in the Battle of Sword Valley, the game's prologue and first tutorial. Wielding the Monado, a legendary sword that it appears only he can use, he almost single-handedly turns the battle from a loss into a win for the Bionis forces. The effort costs him the use of his right arm, but he is taken home to Colony 9 and hailed as "Hero of the Homs". When the colony is unexpectedly attacked a year later, he tries to fight again but is unable to keep control of the Monado, which passes to Shulk instead. From then on, he fights with his left arm, and is no less formidable in combat. After a short rest, he joins Shulk's quest of revenge towards the Mechon (and Metal Face in particular) for their attack.
Dunban is a wise party member. He was somewhat brash and overconfident in the past, owing to being the one with the Monado, but has since learned to be more cautious. He often acts as the voice of reason, as he is the eldest and most-traveled Homs party member. He still defers to Shulk, but will often provide advice as to how Shulk should act. He is also the older brother of Fiora, Shulk's childhood friend who was thought to be killed in the attack.
In combat, Dunban is the group's agility tank: his role is to attract the enemy's attention by dealing large amounts of damage and keep their aggro by dodging their attacks. Concurrently, while his health is lower than the other tanks, his physical power and agility (which translates to both accuracy and evasion) are very high. His arts are designed to inflict high damage and be used one after the other in particular combinations to stack status effects on a single target that most other party members are unable to inflict alone. His high agility also allows him to fight enemies at higher levels than him somewhat easier than other physical party members. However, he needs to successfully deal damage to draw his aggro, he can generally only attack one foe at a time, his best arts are auras that can only take effect one at a time, and his evasive skills are meaningless against ether attacks. As a result, he fares poorly against large groups or ether-based enemies.
As a costume
Shulk's black costume is based on Dunban's color scheme. Additionally, Dunban is also the basis for a paid downloadable content costume for Mii Swordfighters. Nintendo also released a QR code for those who wish to have the exact Mii used in the costume's advertising.
Dunban appears as a trophy in both versions.
Dunban returns as part of Shulk’s Final Smash, Chain Attack, alongside Riki and the newly added Mecha-Fiora.
As a costume
Dunban's outfit returns for the Mii Swordfighter.