Helm of Certain Sanity

Wondrous item, very rare (requires attunement)

Crafted by those who wished to shield their perceptions against mind-bending horrors from beyond, this headgear protects against the loss of mental faculties.

While wearing it, you have a +2 bonus to all Intelligence, Wisdom or Charisma saving throws. You are immune to the spells confusion, feeblemind, and similar effects and gain advantage on saving throws against illusions.

These protections come with a price, however, as the helm of certain sanity also leaves you unable to perceive creatures or spells with the mythos subtype (see sidebar), as if you were blinded and deafened to them. This also makes you immune to gaze attacks or similar sight-based special abilities used by such creatures but also imposes disadvantage on any Intelligence checks to learn about such creatures or their abilities. If you are attacked by a mythos creature or spell, you can perceive it as if it had half cover, appearing only as a dim, threatening shape, for 1d4 rounds.