This page of the Demonomicon has written in code the true names of numerous fiends, listed in no order or organization.

You can spend an action to read a name from the list, after which the name disappears and reappears on a different page of the Demonomicon. When you do, choose a random fiend with the Innate Spellcasting trait that isn’t legendary. You may immediately cast a spell from that trait without expending a spell slot, and without requiring material components.

You may take this action twice, after which the page becomes unreadable until the next dawn. Additionally, after each time you take this action, you must roll a DC 13 Charisma check. On a failed check, the page is incinerated, destroyed by the named fiend’s ire.

Notes: Consumable