Silvershout

2nd-level abjuration
Casting time: 1 action
Range: Self (30-foot cone)
Target: All creatures in a 30-foot cone
Components: V, S, M (ounce of silver powder)
Duration: Instantaneous
Classes: Bard, Cleric
Subclasses:

You unleash a shout that coats all creatures in a 30‑foot cone in silver dust. If a creature in that area is a shapeshifter, the dust covering it glows. In addition, each creature in the area must make a Constitution saving throw. On a failed save, weapon attacks against that creature are considered to be silvered for the purposes of overcoming resistance and immunity to nonmagical attacks that aren’t silvered for 1 minute.