Hypnosium

Hypnosium is a rare, psychoactive element found only within subterranean rock formations within the Gwani Valley in Northern Californa. It is one of only six known elements to have a negative atomic weight. It emits a unique form of radiation that affects only sentient minds, creating extreme suggestibility through harmonizing with alpha brain waves. In trace amounts the effect is negligible unless the material is present within the brain matter itself.