By casting this spell, you imbue a piece of ammunition to have greater effect on a specific target. To this end, you need something directly associated with the creature for which the arrow is intended—a drop of its blood, a strand of its hair, an item of clothing it recently wore, or something similar—which is consumed in the casting of the spell. For the next 24 hours, if the ammunition is used to make a ranged attack against the specific target and it hits, it deals an extra 6d10 radiant damage to the target and stuns it for 1 round. If the target makes a successful Constitution saving throw, it takes half as much radiant damage and is not stunned. If the attack is a critical hit, the creature has disadvantage on its saving throw.