The Demonologist

Though most of these binders and summoners strive for goodness, there are some who see this practice as evil. The reality is that a demonologist usually seeks to learn on how to better fight against demons and devils.

While some mortals forge wicked contracts with these fiends to gain incredible abilities, a demonologist is willing to study the spells and rituals to summon and bind these fiends as their servants. These wizards exert tremendous talents and capability where other wizards would fatally fail.

Profane Spellbook

Beginning at 2nd level, while holding your profane spellbook, you have the following benefits:

• You can use it as a spellcasting focus for your spells.
• You have advantage on ability checks related to information about fiends.
• You can speak, read, and write Abyssal and Infernal.
• You can use an action to telepathically communicate with a fiend that you can see or hear.
• You have advantage on Constitution saving throws you make to maintain concentration on a spell that summons or targets fiends, and you don't have to make the saving throw on such spells as a result of taking damage.

If you lose your profane spellbook, you can expend a spell slot of 1st-level or higher to transform a mundane or magical spellbook into a profane spellbook, retaining its previous properties. The spells granted by the features of this Arcane Tradition always appear in a newly transformed profane spellbook.

Fiendish Servant

While holding your profane spellbook, you can cast each of these spells without expending a spell slot once before you have to finish a long rest. When you cast the find familiar spell in this way, the familiar is a fiend instead of a beast, and you can choose for the familiar to take the form of any Small or Tiny fiend that has a challenge rating of 1 or lower, in addition to the normal forms.

Demonic Ward

While holding your profane spellbook, you can cast the magic circle spell without expending a spell slot, but only targeting fiends and only in its reverse direction. When you cast the spell in this way, a fiend summoned in the magic circle is under your control for the duration of the spell, regardless of the spell's description. You can command the fiend to move in and out of the magic circle freely thereafter.

If the spell ends while the fiend still has hit points and the magic circle is still active, the fiend instantly teleports back into the magic circle and acts according to the spell's description as normal. Otherwise, the fiend disappears after 1 round back to its plane of existence.

Diabolic Strings

While holding your profane spellbook, you can cast the planar binding spell without expending a spell slot once before you have to finish a long rest, but only targeting a fiend that has a CR equal to half your wizard level (rounded up) or lower. When you cast the spell in this way, you can use a bonus action to speak the fiend's true name and bind the fiend to a page of your book, to summon a fiend already bound to your book in an unoccupied space you can see, or to release it from your servitude and send it back it to its original plane of existence. A fiend bound to your book can remain as your servant indefinitely, and you can have a maximum number of fiends bound to the book equal to half your wizard level (rounded up).

If you have at least one fiend bound to your book and the book is on your person, you gain the following benefits:

• You can telepathically communicate with the fiend.
• You have a bonus to ability checks related to recalling information about fiends equal to the number of fiends bound to your profane spellbook.
• You gain one special sense of one of the fiends of your choice.
• You have resistance to fire damage.

When you summon a fiend bound to your profane spellbook, the fiend gains the following benefits:

• Once per turn, the fiend can deal extra fire damage equal to your wizard level.
• When you cast a spell, the fiend can deliver the spell as if it had cast the spell, using its reaction to do so. If the spell requires an attack roll, you use your spellcasting modifier for the roll.
• When a creature enters the fiend's reach, the fiend can use a reaction to make a melee attack against that creature, or to move up to its movement speed without provoking opportunity attacks.
• The fiend gains temporary hit points equal to your wizard level + your Intelligence modifier. Once the fiend gains temporary hit points this way, it can't do so again until you finish a short rest.

In addition, you can use an action to release a fiend bound to your profane spellbook back to its plane of existence and immediately gain advantage on saving throws against spells and other magical effects for the next minute. Once you use this action, you can't do so again until you finish a long rest.

Dark Empowerment

While holding your profane spellbook, you can cast the spell once without expending a spell slot, but you can only choose a demon prince or equivalent as the entity. You can't cast the spell this way again until you finish a long rest.

A fiend summoned by this spell using this feature must succeed on a Charisma saving throw or be forced to fulfill the task you ordered it to complete without requiring any payment, unless the task would cause harm to the fiend. The fiend has disadvantage on the saving throw if you say its true name as part of the summoning.