Crown of Infernus

You place the horns upon your head and feel the searing might of infernal magic weld the horns to your brow. For the duration of the spell, spells that deal fire, cold, or lightning damage add your Charisma modifier.

In addition, once before the spell ends, you can use an action to channel this infernal might. One creature that you can see and that can hear you within 120 feet must make a Charisma saving throw against your spell save DC. On a failed save, that creature loses the ability to speak for 3 turns. They can not communicate with allies through words, or cast spells that have a Verbal component.