Holy Avenger

You gain a +3 bonus to attack and damage rolls made with this magic sword. While you are attuned to the sword and use it to attack a fiend or undead, on a hit it deals an extra 2d10 radiant damage. In addition, while drawn the sword creates an aura in a 10-foot radius around you. You and friendly creatures in the aura gain _advantage_ on _saving throws_ against spells and other magical effects. If you have 17 or more levels in the herald class, the aura increases to a 30-foot radius.