Wondrous Item

Legendary Requires Attunement

Resistance

While attuned to the artifact, you have resistance against piercing damage.

Cantrip

While attuned to the artifact, you can use an action to cast vicious mockery from it.

Immunity

While attuned to the artifact, you are immune to disease.

Health Recovery

While attuned to the artifact, you regain 1d6 hit points at the start of your turn if you have at least 1 hit point.

Hell Fire

While attuned to the artifact, all holy water within 10 feet of you is destroyed.

Destructive Touch

The first time you touch a gem or piece of jewelry while attuned to this artifact, the value of the gem or jewelry is reduced by half.

Dependancy

While attuned to the artifact, you are blinded when you are more than 10 feet away from it.

Death Bringer

Creatures with a challenge rating of 0, as well as plants that aren't creatures, drop to 0 hit points when within 10 feet of the artifact.

Quest Giver

When you first attune to the artifact, it gives you a quest determined by the DM. You must complete this quest as if affected by the geas spell. Once you complete the quest, you are no longer affected by this property.

Adjusted Ability Scores

After you spend the requisite amount of time reading and studying the book, one ability score of your choice increases by 2, to a maximum of 24. Another ability score of your choice decreases by 2, to a minimum of 3. The book can't adjust your ability scores again.

Mark of Darkness

After you spend the requisite amount of time reading and studying the book, you acquire a physical disfigurement as a hideous sign of your devotion to vile darkness. An evil rune might appear on your face, your eyes might become glossy black, or horns might sprout from your forehead. Or you might become wizened and hideous, lose all facial features, gain a forked tongue, or some other feature the DM chooses. The mark of darkness grants you advantage on Charisma (Persuasion) checks made to interact with evil creatures and Charisma (Intimidation) checks made to interact with non-evil creatures.

Command Evil

While you are attuned to the book and holding it, you can use an action to cast the dominate monster spell on an evil target (save DC 18). You can't use this property again until you complete a long rest.

Dark Lore

You can reference the Book of Vile Darkness whenever you make an Intelligence check to recall information about some aspect of evil, such as lore about demons. When you do so, double your proficiency bonus on that check.

Dark Speech

While you carry the Book of Vile Darkness and are attuned to it, you can use an action to recite word from its pages in a foul language known as Dark Speech. Each time you do so, you take 1d12 psychic damage, and each non-evil creature within 15 feet of you takes 3d6 psychic damage.

Destroying the Book

The Book of Vile Darkness allows pages to be torn from it, but any evil lore contained on those pages finds its way back into the book eventually, usually when a new author adds pages to the tome.

If a solar tears the book in two, the book is destroyed for 1d100 years, after which it reforms in some dark corner of the multiverse.

A creature attuned to the book for one hundred years can unearth a phrase hidden in the original text that, when translated to Celestial and spoken aloud, destroys both the speaker and the book in a blinding flash of radiance. However, as long as evil exists in the multiverse, the book reforms 1d10 x 100 years later.

If all evil in the multiverse is wiped out, the book turns to dust and is forever destroyed.

The contents of this foul manuscript of ineffable wickedness are the meat and drink of those in evil's thrall. No mortal was meant to know the secrets it contains, knowledge so horrid that to even glimpse the scrawled pages invites madness.

Most believe the now long gone lich-god Vecna authored the Book of Vile Darkness. He recorded in its pages every diseased idea, every unhinged thought, and every example of blackest magic he came across or devised. Vecna covered every vile topic he could, making the book a gruesome catalogue of all mortal wrongs.

Other practitioners of evil have held the book and added their own input to its catalogue of vile knowledge. Their additions are clear, for the writers of later works stitched whatever they were writing into the tome or, in some cases, made notations and additions to existing text. 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.

Nature can't abide the book's presence. Ordinary plants wither in its presence, animals are unwilling to approach it, and the book gradually destroys whatever it touches. Even stone cracks and turns to powder if the book rests on it long enough.