Plague Domain

Clerics of the Plague Domain are Carriers of their deity's will, spreading sickness and famine to all who come across their paths. They view the sickness they spread as the blessing of their god choosing those who are worthy as they travel. Able to spread and corrode even the toughest of foes with a single look, many people view the Plague Clerics as repulsive beings, shunned and possibly even outcast if exposed for their beliefs. Thus, many followers choose to either practice in secret or live in villages together, where they plan their next move to spread the love of their patron to all.

Domain Spells

Cleric Level	Spells
1st	detect poison and disease, ray of sickness
3rd	lesser restoration, protection from poison
5th	spirit shroud, bestow curse
7th	blight, vitriolic sphere
9th	contagion, greater restoration

Bonus Cantrips

When you choose this domain at 1st level, you gain the Infestation and Poison Spray cantrips. For you, these count as cleric cantrips.

Channel Divinity: Trial of the Worthy

Starting at 2nd level, you can use your Channel Divinity to weave the toxins of your deity into the enemy's body, testing their worth.

As an action, you present your holy symbol, and all creatures of your choice within 30 feet of you must make a Constitution saving throw. If the creature fails the saving throw, they take necrotic damage equal to your cleric level at the beginning of each of its turns for 1 minute, as disease and poison corrode it from the inside. If the creature succeeds on its saving throw, they only take half damage, rounded up. Undead, constructs, and creatures without blood flow automatically succeed on the saving throw.

Beginning at 5th level, when a creature fails its saving throw against your Trial of the Worthy feature, they gain a level of exhaustion, as the disease starts interfering with their nervous system.

Emissary of Disease

Starting a 6th level, your ability to control and manipulate poisons and disease has strengthened your body and your attacks. You gain resistance to poison damage, as well as immunity to diseases and the poisoned condition. In addition, whenever you deal poison or necrotic damage, the damage ignores resistance, as your diseases and poisons have become advanced and unique to many creatures.

Side Effects

At 8th level, the disease you spread leaves residual effects of the creature, even after contact. Whenever you damage an enemy with poison or necrotic damage, they take a reduced damage die equivalent to the dice rolled for that source of damage at the beginning of their turn. The creature can only suffer from one of these effects at a time, and the strongest one occurs. 

For example, if you dealt 4d8 necrotic damage to an enemy, they take an equal amount of dice (4) but at a reduced die, so d6 instead of d8, d10 instead of d12, d4 instead of d6, and so on. If you were to hit a creature twice in one turn, or twice before the start of their turn, the strongest dice number would be rolled (d8 trumps d6 and so on), regardless of the amount of dice rolled.

When you reach 14th level, the extra damage becomes equivalent to the type of dice rolled on the initial damage.

Lingering Miasma

At 17th level, your constant engulfment in the glory of your deity has left an eternal mark on your soul. Whenever a creature within 10ft. of your successfully lands an attack against you, that creature takes necrotic or poison damage (your choice) equal to half your cleric level.