Whispers of Madness

You whisper maddening thoughts into the mind of a creature you can see within range who can hear you. The target must make an Intelligence saving throw. On a failed save, the target suffers a Short Term Madness (DMG p. 259) for the spell's duration. You must use your action on subsequent turns to maintain the spell by whispering more maddening thoughts. Otherwise, the spell ends early at the end of your turn.