Sling Stone of Screeching

This sling stone is carved with an open mouth that screams in hellish torment when hurled with a sling. Typically, 1d4 + 1 sling stones of screeching are found together. When you fire the stone from a sling, it changes into a screaming bolt, forming a line 5 feet wide that extends out from you to a target within 30 feet. Each creature in the line excluding you and the target must make a DC 13 Constitution saving throw. On a failure, a creature takes 2d8 thunder damage and is knocked prone. On a success, a creature takes half the damage and isn't knocked prone. Make a ranged weapon attack against the target. On a hit, the target takes damage from the sling stone plus 3d8 thunder damage and is knocked prone. Once a sling stone of screeching has dealt its damage to a creature, it becomes a nonmagical sling stone.