Light of the Vigil

While holding the Moonlit Vigil Mace, when a creature Heswyn can see within 30 feet is hit by an attack, he can use his reaction to impose disadvantage on that attack roll. He can use this feature a number of times equal to his proficiency bonus, and he regains all expended uses when he finishes a long rest.

Additionally, once per long rest, when he uses this reaction while in dim light or darkness, the attacker takes radiant damage equal to his proficiency bonus + his Wisdom modifier.