Brevelmouth’s Withering Vow

You invoke the vow that sealed Nanna’s voice, cursing a creature you can see within range. Invisible strands of dark thorn wrap around the target’s throat and tongue, choking eloquence and corrupting magic.

While cursed:

• The creature must roll a d6 and subtract it from all Charisma checks involving speech (Deception, Persuasion, Performance) and verbal spellcasting checks.
• Whenever the creature attempts to cast a spell with verbal components, it must first succeed on a Constitution saving throw.
  • On a failed save, the spell fizzles in its throat—the spell fails, and the slot is wasted.
  • On a successful save, the spell is cast, but the creature’s voice cracks unnaturally, causing disadvantage on its next Charisma check.

At the start of each of its turns, the creature may make a Charisma saving throw. On a success, the curse ends early.