Dwarrowdelf Axe is one of my favorite weapons in the game. Despite the fact that it can only attach to a dwarf and is restricted, it does have a range of versatility in that dwarf allies are eligible for the axe. You can't pass up it's efficiency of one cost for what is effectively two attack. A must for any dwarf deck with Tactics.
As the other comment suggests, it's easy to overlook that it's Dwarf *characters*, meaning Dwarven heroes OR allies can use it. — ggl3dde 1