Blade of Hollow Steel

When this spell is casted a blade appears at any unoccupied point within range, or in the hands of an ally within range. The attack roll bonus for this blade is equal to the users dexterity modifier. Anybody can use this weapon, but the caster has proficiency with this weapon, and can spell attack modifier to the attack roll. The damage roll is 1d10. The blade will break after making 4 successful attack rolls.