Helm of the Justicars

This helm once belonged to Grand Mage-Arbiter Elodie Scolian, the preeminent leader of the surviving Justicar order. Designed to eliminate the threat that all mages pose to the nonmagical populace, the wearer of this helmet has an uncanny resilience against spells of all kinds. While wearing this helmet, you gain a +1 bonus to AC, you have advantage on saving throws against spells and other magical effects, and spell attacks have disadvantage against you. In addition, the helm has 12 charges and regains 2d6 expended charges daily at dawn. Whenever you're affected by a spell while wearing this helmet, you can use your reaction to learn the level of the spell and expend any number of charges from the helm (minimum 1 charge). If the number of charges is equal to or greater than the level of the triggering spell, you are unaffected by it. A cantrip is considered to be a 1st-level spell for the purposes of this property.