The Deep Domain focuses on gluttony as a medium for strength.  Aldritch, Devourer of Gods, is a mortal deity who lost his humanity when at one point he was a right and proper cleric.  So it was said he had a terrible habit of eating men until he bloated like a drowned pig, and then softened into sludge.  Through his gratuitous consumption he ascended into his mantle of Saint of the Deep, not for virtue, but for might.

The Cathedral of the Deep promotes using the remains of adversaries, dregs as they're better known, to attain ample strength.  Doing so taps into the bedrock of the world, where existence coalesces, in a place simply known as 'the Deep.'  A gathering of sediment, soul and flesh, awaits to build a devoted, to ascend them.  Only the profane and truly evil claim influence over this domain.  However, due to the aggressive and dangerous nature of this faith any other members devoted to other faiths, domains, and temples can, and likely may, be hostile towards the Aldritch Faithful.  Many of those from Deep should expect to be turned away from other temples, refused aid, or even hunted down.

 Gluttony is strength, starvation is sacrilege.

*Your Spell Save DC and Spell Attack Modifiers rely on your Intelligence modifier instead of your Wisdom modifier.

Channel Divinity: Gluttony

A pact with Devourer of Gods inspires you to consume, and so you shall.  Fear not the dark and let the feast begin.

Beginning at 2nd level you can eat the remains of a fallen foe (must be recently dead or immobile target) to gain 1d10 of your total hit points.  If the act is cannibalism, anyone observing must immediately make a Constitution saving throw DC 12.  Those who fail the save must make the next roll at a disadvantage.

You may use this feature a number of times equal to your class level before needing a short or long rest.

Rose of Aldritch and Deep Domain Expanded Spell List

Through blood and flesh is strength gain, and only through these is the Devourer of Gods paid proper tribute.

Beginning at 1st level you obtain the Rose of Aldritch, holy symbol of the Deep Domain. You may offer appeasement through flogging to trigger an awakening, just as the Good Father once did.  Take 1d4 of melee damage per Cleric level, however, for the next 1 minute any spell you cast that requires a hit roll lands successfully regardless of the target's spell save.

DEEP DOMAIN EXPANDED SPELL LIST

*Your Spell Save DC and Spell Attack Modifiers rely on your Intelligence modifier instead of your Wisdom modifier.

Deep Domain Spells:  Deep Soul and Lifehunt Scythe

To appease your growing hunger you learn to cast spells to deplete the lifeforce, or even steal it, from others.  Beginning at 3rd level you learn your next two divine domain spells: Deep Soul and Lifehunt Scythe.

Deep Soul

Casting Time: 1 Action

Range: 60ft

Components:  V, S, M (Drop of Blood or Crumbled Marrow)

Duration: Instantaneous

Hurl the sediment of men in a ranged spell attack.  On hit target takes 1d12 of necrotic damage.

*This spell cannot be cast at higher levels however it can be cast as many times as you can cast a cantrip.

Lifehunt Scythe

Casting Time: 1 Action

Range: 10ft radius

Component: V, S

Duration: Instantaneous

The dream of a blade comes to life, slicing your enemies in twain with a melee spell attack. On a hit, target takes 1d10 of necrotic damage and you gain life equal to half the total amount of necrotic damage dealt rounded up.

At Higher Levels: At higher levels, when you cast this spell at spell slot level 4 or higher the spell damage increases by 1d6 for each slot level above the 3rd.

 

Deep Domain Spells:  Atonement and Great Deep Soul

Dark sediment accumulates in your soul, soon it drips from your sight.  Beginning at 5th level you learn your next two divine domain spells: Atonement and Great Deep Soul.

Atonement

Casting Time: 1 Action

Components: V, S, M (Tears)

Range: 60ft

Duration: 60 seconds

Target has aggression range increased, making enemies target the spell's target aggressively for the duration.  This is the tale known by exiles, who believes it carries words of forgiveness. Cursed journeys, too, must come to an end.

At Higher Levels:  When you cast this spell using a spell slot 6th level or higher, the duration increases by 30 seconds for each spell slot beyond the 5th.

Great Deep Soul

Casting Time: 1 Action

Components: V, S, M (Cup of Blood or Bone)

Range: 60ft

Duration: Instantaneous

Make a ranged melee spell attack, on hit deal 2d12 of necrotic damage.  These souls stagnate, pleasing Arch Deacon McDonnell, as they represent the glorious bedrock of this world.

At Higher Levels: When you cast this spell using a spell slot 6th level or higher, add 1d12 of necrotic damage for each spell slot level this spell is cast beyond the 5th.

 

Deep Domain Spells:  Dorhys' Gnawing and Great Soul Dregs

Those who linger too long on the brink of the deep will often slip.  Beginning at 7th level learn your next two divine domain spells: Dorhys' Gnawing and Great Soul Dregs.

Dorhys' Gnawing

Casting Time: 1 Action

Components: V, S, M (Dead Insects and Cup of Blood)

Range: 60ft

Duration: Instantenous

Summon a swarm of insects derived from the texts of the depraved evangelist.  Make a ranged necrotic spell attack against target, on hit the target takes 3d10 necrotic damage and must make a Constitution saving throw.  If the target fails the save it begins bleeding out and must take 1d8 of necrotic damage after the end of its action step until it succeeds the save.

At Higher Levels:  When you cast this spell using a spell slot 8th level or higher, add an additional 1d10 of necrotic damage on hit and 1d8 of necrotic damage to the failed saving throw for each spell slot beyond the 7th.

Great Soul Dregs

Casting Time:  1 Action

Components:  V, S, M (Flesh of Recently Dead)

Range:  45ft

Duration:  Instantaneous

Fire forth souls that have stewed in the deep for ages, steeped in darkness that have a grave likeness to men.  Make a ranged melee spell attack, on hit target takes 4d12 of necrotic damage.

At Higher Levels:  When you cast this spell using a spell slot 8th level or higher, add 1d12 of necrotic damage for each spell slot beyond the 7th.

 

Deep Domain Spell: Dreg Heap Gospels

Learn the final divine domain spell: Dreg Heap Gospels.  Within the deep sea a vision has become whole from the ageless, stagnating dregs.

Casting Time: 1 Turn

Components: V, S, M (Vial of Old Blood)

Range: 5ft from Self

Duration:  Instantaneous

Give form of ancient sediment, horrifying in likeness to men, restless and ever seeking purpose.  Bring forth the murkmen, summoning a number of murkmen equal to your proficiency bonus.  Each murkman  has 35 hit points, AC 15 , and makes a melee attack that deals 2d12 of necrotic damage.  Command all of your murkmen as 1 action, and they have the same initiative you do at the time of their summoning.

At Higher Levels:  When you cast this spell using a spell slot 10th level or higher, summon an additional murkman for each spell slot beyond the 9th.

Channel Divinity: Shared Vision

Continue the vigil over Aldritch's vision, the rock where his church was built, and spread his gospels.

Beginning at 6th Level domain spells you cast create visions of the deep sea, casting a glimpse into the true, dark nature of existence.  Spells that hit automatically instill terror into the target.  Targets that are terrified make a Constitution save.  If the target fails its save, the spell causes the target to fall prone.  If the target succeeds its  save, the spell causes the target to flee up to 15ft instantly, using the targets movement action for the turn. 

Channel Divinity: Black Hymns

Beginning at 8th Level, as a bonus action you may read from the book of your divinity, the Black Hymns.  Targets within a 40ft radius must make an Intelligence save.  Any targets who fail this save hear your disturbing chant, causing targets to lose all resistances for a number of turns equal to your Intelligence Modifier.  You may use this feature once before a short or long rest.

Channel Divinity: Boar of the Deep

Gluttony has ensured your seat of power, darkness steeped into your veins.

At 17th level your gluttony allows you to consume the knowledge of others.  If you consume a spellcaster using your Gluttony feature you gain visions of another time, allowing you to learn 1 spell from the consumed target's school of magic 2 levels below your highest spell slot level.  Once you have learned 2 spells using this method you cannot learn anymore, these are permanent and cannot be changed once each have been selected.  (Consult your DM as to the target's school of magic before consumption.)

Despite your immense power, your gluttony has altered your physical form terrifying and unsettling others around you.  Any Charisma related rolls that you make must take a -3 penalty unless they pertain to an evil action.