We delved back into the Underdark on Tuesday’s post (found here) and continuing in that same venue, we look at something fun I’ve been thinking about since Out of the Abyss came out. An Unearthed Arcana article on Abyssal Tieflings and demon summoning spells prompted some further thought. My Drow article also brought back the close ties between Drow and demons since Lolth is the demon spider queen, her influence on this relationship has been felt across many novels, games, and adventure modules.

Design Thoughts
So while the ideal mechanic would be a class that enjoys summoning demons, for a Warlock it would be tough. Especially since summoned creatures are very powerful in 5th Edition. It can be quite abusive. If we wanted the warlock to use the demon summoning spells from the Old Black Magic Unearthed Arcana article, I would consider having some of them as Invocations that use a warlock spell slot and cannot be used again until finishing a long rest.

The 1st level feature was under the pretext of the theme fora warlock the brings ruin and poison damage was an option. I decided on psychic damage for the 2nd damage modifier to gain a bonus, since there are very few spells that dealt psychic it seemed fair. Plus psychic damage fit the alien, otherworldly theme place by the Out of the Abyss adventure.

The 6th level warlock feature was something inspired by the Abyssal Tiefling idea, having different features rotate after each long rest sounded fun.

A warlock 10th level feature is usually defensive in nature, I wanted to tie in the mania associated with demons and the abyss. What better way than to invoke madness in your foes to hurt their allies. I figured since the creature would to have make a Wisdom saving throw and also an attack roll. To me that’s a lot of hurdles to get this trick to work. I added clauses for whenever there legal targets. So it shouldn’t be exploited too often.

The final feature at 14th level is traditionally quite a game changer. I wanted to do something similar to the destructive fury of an Infernal pact Warlock but be impactful to multiple foes instead and for a longer duration. The inclusion of disadvantage to charm and fear effects was an added touch to give the warlock options in battle.

So I present to you…

Abyssal Pact Warlock and her Demon Lord patron

Abyssal Pact

Expanded Abyssal Spells

1st bane, Tasha’s hideous laughter
2nd blindness/deafness, phantasmal force
3rd lightning bolt, stinking cloud
4th confusion, phantasmal killer
5th cloudkill, legend lore

Soul of the Defiler: Starting at 1st level, you gain poison spray as a cantrip. If you already know it, you can select another cantrip from the warlock spell list. This doesn’t count against the number of cantrips you know. You gain resistance to poison damage. When you cast a spell that deals poison or psychic damage, you add your Charisma modifier to that damage.

Essence of Chaos: Starting at 6th level, you begin to channel the chaotic and destructive energies from your demonic patron. But like the very plane of the Abyss itself, there are many layers and expressions that only be fathomed. Whenever you complete a long rest, you gain a feature randomly determined from a short list. Each feature comes with a quirk which last until the end of your next long rest.

At the end of each long rest, you lost your features and randomly roll on the table again to determine your new features. You replace that feature with your new feature from the table.If you roll a feature you had gained at the end of your previous long rest, roll again until you get a different result.

Essence of Chaos Features

d6
1 Shadows envelop your form, your eyes turn to a piercing white. You can cast darkness at will. You gain disadvantage to Wisdom (Perception) checks and attack rolls while in direct sunlight or bright light. You become blinded whenever in the area of a daylight spell.
2 Your skin turns ashen and the smell of cinder fills the air around you. As an action, you can summon an aura of flames 10 feet from you. Creatures that enter or start their turn in the aura are dealt 2d6 + your Charisma modifier in fire damage. You are vulnerable to cold damage.
3 Spectral appendages emerge from your back, spider-like in nature; your eyes change into tiny dots. You gain a climb speed equal to your land speed. You also gain Darkvision up to 60 feet, if you already have Darkvision, you increase the range by 60 feet. You also have advantage on Strength (Athletics) and Dexterity (Acrobatics) checks. You are Vulnerable to Lightning and Thunder damage.
4 Crimson energy surrounds you but you skin turns pale causing you to feel sluggish. You gain temporary hit points equal to 10 + your Charisma modifier at the start of each of your turns. Your speed is halved, and your maximum hit points is reduced by your warlock level + your Charisma modifier.
5 Black wings emerge from your back, you feel lighter than air. You grow a pair of bat-like or feathered wings and a fly speed of 30 feet. You gain disadvantage on Strength and Constitution checks and saving throws. You gain Vulnerability to fire damage.
6 Your skin turns pristine and iridescent, but you realize it’s fragile like glass. You add double your proficiency bonus to Charisma checks and you have advantage on saving throws against spells. You gain Vulnerability to bludgeoning, slashing, and piercing damage.

Cloak of Madness: Beginning at 10th level, you instill the very powers of chaos and disorder, transferring it to unsuspecting foes in a desperate moment. Whenever a creature attacks you, you may use your reaction to make it roll a Wisdom saving throw against your spell save DC. On a failed save, the creature attacks a hostile non-ally creature within its reach. If there are no targets available, the attack resolves normally. If a creature cannot be charmed, this feature does not apply to it.

Demonic Herald: Beginning at 14th level, you release the demonic essences you have gathered from the Infinite Layers of the Abyss from your demonic patron and transform into an avatar of chaos and terror. Using an action, you under a transformation as horns, wings, and maybe even a tail emerge from your form. For 1 minute (as if concentrating on a spell) hostile creatures within 30 feet from you have their speed halved and must make a Wisdom saving throw as they suffer mental traumas from your visage. On a failed save, they take 5d6 psychic damage, or half as much on a successful save. Creatures that enter or start their turn within your presence must make Wisdom saving throws for the duration. Additionally, creatures within this this area have disadvantage to saving throws against being charmed or frightened by your spells. Creatures that cannot be charmed or frightened are unaffected. Once you use this feature, you must finish a long rest to use it again.