School of Demonology

As a Demonologist, you have studied the Abyss and its denizens. Chaos is a tool and one you wield well. Your studies keep you up to date on both the oldest and most current profanities of the Abyss and demons.

Abyssal Knowledge

Starting at 2nd level, whenever you make an Intelligence check to discern information about demons or a Wisdom (Survival) check related to the Abyss, you can add double your proficiency bonus to the check. In addition, you learn the language Abyssal if you don't already know it.

Demon Companion

Starting at 2nd level when you select this school, you can use your action summon a demon from the Abyss. You choose the type of demon that is summon, but it must have a Challenge Rating equal to or lower than half your proficiency bonus (rounded down). If you know a demon's true name, you can choose to summon that specific demon as long as it is of an appropriate challenge rating.

The demon appears in the closest unoccupied space to you. The demon is friendly to you and your companions, and it obeys your commands. In combat, the demon shares your initiative count, but it takes its turn immediately after yours. It can move and use its reaction on its own, but the only action it takes on its turn is the Dodge action, unless you take a bonus action on your turn to command it to take another action. If you are incapacitated, the demon can take any action of its choice, not just Dodge.

The demon remains until it is reduced to 0 hit points, until you use this feature to summon a demon again, or until you die. Anything the demon was wearing or carrying is left behind when the demon vanishes.

Once you summon a demon, you can’t do so again until you finish a long rest.

Master of Binding

Starting at 6th level, you gain a mastery of spells which bind demons and fiends to your will. You ignore immunity to the charmed condition on Fiends. Furthermore, you learn the spell magic circle if you don't already know it. The spell is always prepared, and doesn't count towards the number of spells you can prepare in a day.

Once per long rest, you can cast magic circle as an action, without requiring any components, and without consuming any spell slots. When you cast the spell in this way, the chosen creature type is only Fiends.

Abyssal Strength

Beginning at 10th level, your mastery of abyssal knowledge lets you tap into some demon power. You gain resistance to fire damage, cold damage, and lightning damage.

Mastery of Demonology

Starting at 14th level, when you conjure a demon using your Demon Companion feature, the Challenge Rating of the demon can be equal to or lower than your proficiency bonus.

Furthermore, whenever you cast the magic circle spell naming only fiends, or the planar binding spell targeting a fiend, the spell is cast at 9th level, regardless of what level spell slot you used, if any. Additionally, the fiend has disadvantage on its saving throw against the spell.