Demonology

By their very nature, demons are leeches on the living universe—but the demonologist has mastered harnessing the power of these malefic beings on the field of battle. Warlocks harvest the souls of their defeated enemies; those specialized in the ways of demonology use this life essence to tap into the Void or to pull all manner of abomination from the chaos of the most vile planes.

While such a practice is often considered by outsiders to be wicked and reckless, the demonologist maintains absolute control over the summoned creatures. These malignant entities are fully beholden to—and empowered by—the will of the warlock, until banished to the realm from whence they came. There are more than enough venal farmhands who invoke a demonic force for revenge against a former lover, or stupid merchants who burn an invoice from a debtor with a black candle, badly mangling the ancient name of some once-great demonic power

Demonology is the study and practice of using and amplifying demonic powers and the ability to summon items or Demons, mostly using Soul Shards. 

The craft of conjuration is the primary focus of the warlock, and in taking on the mantle of a demonologist the warlock sacrifices knowledge in other areas of arcane practice.

Expanded Spell List

The demonlolgist lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Fiend Expanded Spells

Spell Level	Spells
1st	absorb elements, find familiar
2nd	find steed, silence
3rd	spirit guardians, summon lesser demons
4th	find greater steed, summon greater demon
5th	infernal calling, antilife shell

Demonology

Starting at 1st level, any creature you summon with a conjuration spell has their creature type changed to demon (the stat block does not change). In addition, you command control over demons in two separate forms: Wild Imps and Demonic Generals. While one form is active, the other is inactive.

Wild Imps. At the start of your turn in or out of combat, you may summon a wild imp. The imp is a very small creature, has a 10 in every stat and 1 hit point, and follows within 5ft of you. You may have a maximum amount of imps equal to your proficiency bonus. As a bonus action you may command the summoned imps to attack a target within 120ft of you. Each imp casts fire bolt, using your charisma modifier for the spell.

Demonic General. As an action, you may summon your demonic general. It appears in an unoccupied space of your choice within 30 feet of you. See its game statistics in the accompanying Demonic General stat block, which uses your proficiency bonus (PB) in several places. The demon is friendly to you and your companions, and it obeys your commands. Any demon who is under your control empowers the general, and while it is out, other demons you summon only serve to strengthen the singular demon. While empowering them, these demons form into it's body, splitting back if it dies, or if you dismiss it as an action. The demon otherwise lasts until dismissed. You can determine the cosmetic characteristics of the demon, but otherwise your choice has no effect on its game statistics.

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, without your verbal commands, but it will follow a command given no matter what (although it still may fail). 

The demon remains until you die, at which point it is no longer bound by you, attempting to kill it's former allies instead. Anything the demon was wearing or carrying is left behind when the demon vanishes.

Once you summon the demon, you can’t do so again until you finish a long rest, but you can expend a spell slot as an action to heal it for 5d10 per level of the slot, even if it would be at 0 hit points, but not dead (it does not have death saving throws, but can never truly die permanently.) 

 

Make No Waste

Starting at 6th level, when a demon under your control dies, you may use their life energy to fuel your magic, filling a soul shard. You have a maximum amount of soul shards equal to your charisma modifier plus your proficiency bonus. You can spend soul shards in the following ways as a bonus action -

Empower The Survivors (2 Soul Shards) - All demons under your control have the extra attack feature, making 2 attacks instead of one for 1d4 minutes, or for one second outside of combat. This does not affect wild imps casting spells.

Empower Your Master (4 Soul Shards) - You expend 4 soul shards to empower yourself, giving you temporary hit points equal to the combined CR of the demons times 2 (min 1, if CR isn't listed or it is below CR 1).

Life Drain - You may expend any number of soul shards; you are healed for the amount of shards expended times your warlock level. You cannot expend shards this way outside of combat.

Soul shards last 1d4 minutes after the demon dies until emptying once again. 

Dark Pact

Starting at 10th level, you make a deal with the devil himself. As an action, you may sacrifice exactly half your maximum hit points, taking that much damage; you create a demonic ward around yourself to ward off harm. 

The ward has hit points equal to twice your warlock level plus the amount of hit points lost. Whenever you take damage, the ward may take the damage instead. If this damage reduces the ward to 0 hit points, you take any remaining damage.

While the ward has 0 hit points, it can't absorb damage, but its magic remains. Whenever you cast an conjuration spell of 1st level or higher, the ward regains a number of hit points equal to ten times the level of the spell.

In addition, if the ward would take fire or poison damage, it absorbs it instead, turning the damage dealt into healing for the ward. 

 This ward does not stack, and lasts until your next long rest.

Demonic Resilience

Starting at 14th level, your magic weaves into your very life energy, making you more capable of taking large amount of damage. You may use an action on a demon you are under complete control of (Any demon not eligible to become a pet will not work for this ability); you tear it's soul from it's body, permanently killing it and empowering yourself. If you use this ability again, the new demon's stats are used and the old demon's soul is completely destroyed. 

While consumed, the soul gives you additional hit dice equal to the demon's challenge rating, which are added to your max hit points. You also gain one proficiency the demon had, and can speak any languages it knew in life fluently.