Master of Fiends

From "Deep Magic" by Kobold Press.

Beings of the Lower Planes dangle promises of power as bait, hoping to lure careless folk into their clutches. Some of those who take the bait have a keen intellect, enabling them to use careful planning that circumvents this damnation—or at least delays it. In this way, power- hungry mages strike bargains and increase their magical might with the knowledge the fiends offer. A master of fiends, as these individuals are called, is either a diabolist (one who deals with devils) or a demonologist (one who traffics with demons). Most common folk care little about the distinction, seeing both simply as servants of evil, but the differences between the two are significant. Diabolists are masters of language and context, knowing that the contracts proffered by devils are complex and meant to mislead, and must be read carefully and fully understood so as to avoid any trickery. Demons have little use for subtlety; they understand and respect only one thing— power. A demonologist must have the magical power to compel such fiends to do their bidding, or they will surely be rent asunder and have their soul carried screaming back to the Abyss by the demon. Either path takes a person willing to risk their immortal soul in the pursuit of power, and few dare to do so.

Dark Arts

Beginning at 2nd level, you gain a bonus spell you can copy to your spellbook at half the cost. You gain a new spell at each level indicated on the following list if you have not already learned the spell. You acquire knowledge of these spells through your trafficking with fiends.

When you attain the appropriate wizard level, add the indicated spell to your spellbook: 2nd level, hellish rebuke; 4th level, enthrall; 6th level, magic circle; 8th level, banishment; 10th level, dominate person; 12th level, mass suggestion; 14th level, plane shift; 16th level, dominate monster; and 18th level, imprisonment.

Fiendish Presence

At 2nd level, you develop a dark aura of either allure or menace. You gain proficiency in Deception, Intimidation, or Persuasion. You can bring this talent to the fore to gain advantage on a single check using the chosen skill. Once you use this feature, you can’t use it again until you finish a short or long rest.

Deception

You gain proficiency with the Deception skill. You can bring this talent to the fore to gain advantage on a single check using the chosen skill. Once you use this feature, you can’t use it again until you finish a short or long rest.

Intimidation

You gain proficiency with the Intimidation skill. You can bring this talent to the fore to gain advantage on a single check using the chosen skill. Once you use this feature, you can’t use it again until you finish a short or long rest.

Persuasion

You gain proficiency with the Persuasion skill. You can bring this talent to the fore to gain advantage on a single check using the chosen skill. Once you use this feature, you can’t use it again until you finish a short or long rest.

Communion at the Crossroads

Tradition states that the devil awaits at the crossroads, looking to bargain with those who seek to sell their souls for glory. When you reach 6th level, you can achieve contact with the lower realms in less dramatic circumstances. For you, any significant liminal space—the threshold between one space and another, such as the edge of a forest, the entrance to a cave, or the doorway leading from a church to its graveyard —will do. In such a place, you can perform a ritual that summons a dark spirit from beyond, a shadowy form that will offer you power for power.

When you do so, you can expend a number of spell slots (equal to your wizard level or lower) in exchange for a pool of an equal number of dice that you can use in one of two ways. You can spend one or more dice as an action on your turn to heal yourself, regaining 1d8 hit points for every die you spend. Or you can spend one or more dice to boost the damage of a spell you cast. Each die you spend adds an additional die of damage to a spell you cast, of the same size used in the spell (d6s for fireball, for example).

Once you use this feature, you cannot use it again until you finish a long rest. Any unused dice in the pool are lost when you rest, and you regain your normal number of spell slots after the rest.

Planar Defense

When you reach 10th level, you have learned to enhance your magic to provide you with greater benefit against extraplanar threats. You are protected not only against attack or betrayal by fiends, but by celestials that would see you judged for your connection with darkness. You have advantage on any saving throws against spells and abilities of celestials or fiends that would cause you to become charmed, frightened, paralyzed, restrained, stunned, or possessed by such a creature.

Additionally, if you have the dispel evil and good spell prepared and a celestial or a fiend attacks you, you can cast that spell as a reaction. Once you do so, you can’t use this additional benefit again until you finish a long rest.

Master of Dark Conjuration

Starting at 14th level, when you cast a magic circle spell that affects fiends, such creatures have disadvantage on any Charisma saving throws made in an attempt to enter or leave the cylinder by teleportation or interplanar travel. In addition, any fiend you summon with a conjuration spell gains 13 temporary hit points.