Shield of the Justicars

One of the original arms from the Upheaval, this shield can be used to release a magically discordant pulse. While holding this shield, you have a +1 bonus to AC. This bonus is in addition to the shield's normal bonus to AC. In addition, the shield has 4 charges and regains 1d4 expended charges daily at dawn. While holding it, when a creature that you can see within 30 feet of you casts a spell, you can use your reaction to expend 1 of the shield's charges and speak its command word. When you do, the target must make a DC 15 Constitution saving throw. On a failed save, the target takes a –2 penalty to its spell attack bonus and saving throw DC until the end of the turn, including against the triggering spell.

A shield is made from wood or metal and is carried in one hand. Wielding a shield increases your Armor Class by 2. You can benefit from only one shield at a time.