Undead Bane

Weapon (any sword), very rare

You gain a +2 bonus to attack and damage rolls with this weapon. If you hit an undead creature, if must make a DC 15 Wisdom saving throw or become frightened of you for one minute. It can attempt a new saving throw at the end of each its turns, ending the effect on a success. If you hit an undead creature of Challenge 1/2 or lower, it is destroyed.