Instill Madness (5e Spell)
From D&D Wiki
One creature of your choice within range, that is aware of you and frightened of you, must succeed on a Wisdom saving throw against your spell save DC. On a failure, the creature must roll on the d100 short-term madness table. The effect lasts for 1d10 minutes. You cannot cast this on a creature already suffering madness.
At Higher Levels: When you cast this spell using a spell slot of 4th level or higher, you can target one additional creature for each slot level above 3rd.