Tome of Enshrouding

The contents of this evil manuscript are that of Tiamat's writing. It contains evil knowledge in Draconic writing. There are places where pages are missing, torn or covered so completely with ink, blood, and scratches that the original text can't be divined. A creature attuned to this tome must spend 80 hours reading and studying it to digest its content and use its Enshrouding and Divination property. If you die while attuned to the tome, Tiamat claims your soul. You can't be restored to life by any means while your soul remains imprisoned.

Spells. While holding the tome you can cast the following spells from it:

• Divination
• Enshrouding

Once you use the tome to cast a spell you can't cast that spell again until the next long rest.

Divination. You can cast the Divination spell as a ritual, but the Casting Time is an Action instead of the normal ritual casting time. When cast in this way, you can contact only Tiamat.

Enshrouding. While wearing heavy armor, you can use a Magic action to enshroud yourself with Draconic ethereal scaling for 8 hours. You gain + proficiency bonus to your armor class, which decays by one upon getting hit by a bludgeoning, piercing or slashing attack.

Shattered Aegis. Upon the shroud's bonus getting reduced to zero, it shatters violently. This leaves you vulnerable to a damage type of Tiamat's chromatic dragon heads, chaotically imbued by the Tome. The Tome has a small chance to curse you with any vulnerability of it's choosing. The vulnerability lasts until the end of your next turn.