Pyramids of the Abjurer

The pyramids of the abjurer are a set of three perfectly geometric pyramids which radiate strong abjuration magic. While attuned to these pyramids, they gently float around you, circling just within reach. The pyramids have three charges, and regain 1d4-1 charges each day at dawn. While attuned to the pyramids, you can use your reaction and expend a charge to cast the shield spell. Additionally, whenever you are targeted by a spell of 3rd level or lower, you can use your reaction and expend a number of charges equal to the level of the spell to automatically negate the spell’s effects. Negating a cantrip in this way requires you to expend one charge. When you expend the final charge from the pyramids, they explode outwards in a burst of energy, forcing each creature within 15 ft. to make a DC 16 Strength saving throw, causing them to take 4d10 force damage and be pushed back 15 ft. on a failed save, or take half as much damage without being pushed on a success.