Deep Magic Volume 2 (p.235)
Venemous Thoughts
3-level Necromancy
Casting Time: 1 action
Range/Area: Self
Components: Verbal, Somatic, Material
Materials: the tongue of an asp
Duration: 1 hour
Attack/Save: INT Save
Damage/Effect: Poison
You protect your mind with psychic poison. Until the spell ends, each time a creature attempts to read or detect your thoughts, speak with you using telepathy, influence your dreams, or perceive you through magical scrying sensors, it must make an Intelligence saving throw, taking 4d10 poison damage on a failed save, or half as much damage on successful one.
Available for: Bard, Cleric, Druid