Stolen Thunder

This bodhrán drum is crafted of wood from an ash tree struck by lightning, and its head is made from stretched mammoth skin, painted with a stylized thunderhead. While attuned to this drum, you can use it as an arcane focus. While holding the drum, you are immune to thunder damage. While this drum is on your person but not held, you have resistance to thunder damage. The drum has 10 charges for the following properties. It regains 1d6 + 4 expended charges daily at dawn. In addition, the drum regains 1 expended charge for every 10 thunder damage you ignore due to the resistance or immunity the drum gives you. If you expend the drum's last charge, roll a 1d20. On a 1, it becomes a nonmagical drum. However, if you make a Charisma (Performance) check while playing the nonmagical drum, and you roll a 20, the passion of your performance rekindles the item's power, restoring its properties and giving it 1 charge. If you are hit by a melee attack while using the drum as a shield, you can use a reaction to expend 1 charge to cause a thunderous rebuke. The attacker must make a DC 17 Constitution saving throw. On a failure, the attacker takes 2d8 thunder damage and is pushed up to 10 feet away from you. On a success, the attacker takes half the damage and isn't pushed. The drum emits a thunderous boom audible out to 300 feet.