The effects of this spell are determined by the gems set into the ring for the material component.

Emerald. You can eradicate something you remember from your mind and the minds of any number of creatures of your choosing.

Ruby. You can name a sentient being you have met and erase their existence from your mind and the minds of any number of creatures of your choosing.

Jet. You can erase a piece of text from the minds of everyone on your current plane, and erase it from every scroll and book as well. Once you do so, the texts become by-and-large jumbled incohesive messes of words that cannot be understood, except by the most insane of minds.

This spell will always affect your memory alongside any otehr targets you choose. Furthermore, when the casting is complete you take psychic damage equal to the number of people you affected, up to one point below your maximum.