A chunk of obsidian formed from the red sand of Avernus by the impact and explosion of one of that plane’s ubiquitous meteors. A berk carrying this on his person can cast spells with no problems when on Avernus (the first layer of Baator).

Any spellcaster without a Spell Key has their magic modified in the following ways when on Avernus:

• Conjuration: Summon Monster spells only conjure creatures native to Baator.
• Divination: Contact Other Plane / Commune and similar spells can only contact deities that live in Baator.
• Necromancy: Raise, Resurrect, Reincarnation, Speak with Dead and similar spells only work for souls that have been sent to Baator.
• Wild Magic: All spells from the school of Wild Magic are cast at -1 caster level. Wild Magic spells of greater than 4th level do not function at all.
• Elemental: Any spell that summons an elemental or accesses the elemental planes will not work. With a spell key it will summon an elemental spirit made of the available materials of the plane, which will always be of Lawful Evil alignment.