Pestilence Domain

Gods of Pestilence include Talona, Incabulos and Morgion, among many others. They are the ones that have brought many terrible plagues upon the material plane. They are typically worshipped by medics and assassins. They teach their followers how to control diseases of the world; allowing them to either tame and cure them or use them for ill means. Clerics of the gods of Pestilence will typically seek the sick with the intention to cure them, obtain samples of a new disease, or are just driven by curiosity.

Decay

Also at 1st level, once per turn when you deal necrotic or poison damage with a spell of 1st level or higher, you may infect one creature that took damage with a decaying plague. The next time the creature is hit by an attack, the creature and up to 3 other creatures you choose within 10 feet of the initial creature take 1d4 necrotic damage and 1d4 poison damage.

Channel Divinity: Patient Zero

At 2nd level, you gain the ability to inflict a disease upon a target creature. It must succeed on a constitution saving throw or become infected. An infected creature is poisoned and all creatures that you designate that start their turn or enter for the first time on their turn within 5ft range of the infected creature must also make the saving throw, risking infection themselves. The disease expires naturally after an hour.

Plague master

Starting at 6th level, you have immunity to disease and can identify any disease with a quick examination. If you have samples from an infected creature, Poisoner’s kit, and an empty vial you may prepare a single dose of a poison during a short rest that inflicts the disease upon its victim.

Potent Spellcasting

Starting at 8th level, you add your Wisdom modifier to the damage you deal with any cleric cantrip.

Harbringer of Pestilence

Starting at 17th level, you can channel an unnaturally powerful disease. As an action, select a number of creatures up to your cleric level within 120ft range. Target creatures must succeed on a constitution saving throw or become infected with a deadly pathogen. Infected creatures have disadvantage on ability checks and take 3d10 necrotic damage and 3d10 poison damage at the end of their turn. Creatures repeat the saving throw at the end of each of their turns, ending the disease on a success. Once you use this feature, you can’t use it again until you finish a short or long rest.

New Spells

Afflicted Crow

Druid, Warlock, Wizard
Necromancy Cantrip
Casting time: 1 action
Range: 60ft
Components: V, S
Duration: Instantaneous

You send forth a spectral crow to maim your enemy. Make a ranged spell attack. On a hit, the target takes 1d4 necrotic damage and an additional 1d4 poison damage. This spell's necrotic and poison damage both increase by 1d4 when you reach 5th level (2d4 and 2d4), and again when you reach 11th level(3d4 and 3d4) and 17th level(4d4 and 4d4).

Alternatively, when you cast this cantrip you can choose an object you can see within range that weighs no more than 1lbs. The crow flies to the item and brings it back to you. If the item is being worn or carried by a creature, that creature can make a Strength or Dexterity (its choice) ability check opposed by an ability check that uses your spellcasting ability to stop the crow from taking the item.

Corpse Explosion

Sorcerer, Warlock, Wizard
5th-level necromancy
Casting time: 1 action
Range: 150 feet
Components: V, S, M (Blood mixed with sulphur)
Duration: Instantaneous

You cause a corpse within range to start rot rapidly, bloating itself with gasses before exploding, sending toxic blood and sharp bones in all directions. The explosion fills a sphere, the radius of which is dependent on the size of the corpse. The radius starts at 10 feet, and increases by 10 feet for each size category above tiny. All creatures within the affected area must make a dexterity saving throw, taking 5d6 necrotic and 5d6 poison damage on a fail or half as much on a success.

At Higher Levels. When you cast this spell using a spell slot of a 6th level or higher, both the necrotic and poison damage increase by 1d6 for each slot level above 5th.

Murder of Crows

Druid, Warlock, Wizard
3rd level necromancy spell
Casting time: 1 action
Range: 60ft
Components: V, S, M (A feather of a crow)
Duration: Concentration, up to 1 minute.

You command a flock of spectral crows to feast upon your foe. Make a ranged spell attack. On a hit, the target suffers 4d8 necrotic damage and is distracted, suffering from a disadvantage on constitution saving throws made to maintain concentration until the spell ends. At the start of their turn, they must make a dexterity saving throw, taking another 4d8 necrotic damage on a fail or half as much on a success. A creature that succeeds on the saving throw frees itself from the crows, ending the spell.

At higher levels. When you cast this spell using a spell slot of 4th level or higher, both the initial and the recurring damage are increased by 1d8 for each slot above 3rd.

Necrosis

Cleric
2nd-level necromancy
Casting time: 1 action
Range: Touch
Components: V, S
Duration: Instantaneous

You cause the flesh of a creature you touch to start decaying. Make a melee spell attack against a creature you can reach. On a hit, the creature takes 3d6 necrotic damage and 3d6 poison damage.

At Higher Levels. When cast using a spell slot of a level 3rd or higher, the damage dice used by this spell increase by 1d6 for each slot level above 2nd.

Panaceum

Cleric, Druid, Ranger
4th-level abjuration
Casting time: 1 action
Range: Touch
Components: V,S
Duration: Instantaneous
You touch a creature and instantly cure all diseases afflicting it. You also cure it of the blinded, deafened, paralyzed and poisoned conditions