Dáin of the Ancient Halls has strong Commander potential as a five-mana Boros legendary creature that can turn a wide Dwarf board into a powerful source of direct damage. With vigilance and haste, Dáin can attack immediately upon entering the battlefield while remaining available as a blocker afterward, giving him useful flexibility in multiplayer games. His attack trigger is where the card becomes particularly interesting, scaling with the number of Dwarves you control.