Oath of Pestilence

Paladins that take an Oath of Pestilence are crazed fanatics that believe their god or gods have sent a plague to the world to test the faith of mortals. These paladins work tirelessly to spread this blight, believing it to be a sacred infection, purifying the world of those unworthy.

The tenets of the Oath of Pestilence are as follows:

Proliferate: You must spread the words of your creed like a disease spreads from person to person. Share what you know, and offer to teach those eager to learn.
Evolve: A disease is only as effective as its ability to adapt to change. You must be the same. Those lacking in resolve will be culled.
Purify: Illness and disease are like wildfire that clears the overgrowth and brush. You are to foster death, so that new life has room to thrive.

Oath of Pestilence Spells

The magic of your oath ensures you always have certain spells ready; when you reach a Paladin level specified in the Oath of Pestilence Spells table, you thereafter always have the listed spells prepared.

Oath of Pestilence Spells

Paladin Level	Spells
3	Grease, Ray of Sickness
5	Melf's Acid Arrow, Wither and Bloom
9	Gaseous Form, Stinking Cloud
13	Blight, Vitriolic Sphere
17	Cloudkill, Contagion

Channel Divinity

When you take this oath at 3rd level, you gain the following two Channel Divinity options.

The Blessed Cloud. As an action, a thick, acrid gas pours out of you from open sores and fetid patches of skin, engulfing the air all around in a choking green. You produce a cloud of plague-filled air in a 150 foot Eminance centered on you for 1 minute. The cloud spreads around corners and over obstacles. Creatures within the cloud lose an accumulating 1 point to their Armor Class at the start of each of their turns. This penalty remains until the creature leaves the cloud or the cloud dissipates after 1 minute, whichever happens first.

Sacred Swarm. As an action, you vomit forth a cloud of thousands of biting black flies in a 15 foot cone in front of you. Creatures in this cone are covered in the plague flies for 1 minute. For the duration, creatures affected have disadvantage on Intelligence, Wisdom, and Charisma saving throws and skill checks, and cannot use their Reaction. Creatures may spend an action on their turn to make a Constitution saving throw against your Paladin spell casting DC to rid themselves of the plague flies.

Aura of Miasma

By 7th level, disease and filth emanates from your very being. You radiate an aura of miasma, and the aura extends 10 feet from you in every direction. Whenever a creature enters a miasma's area for the first time on a turn or starts its turn in a miasma, you may have it make a Constitution save against your spell DC. 

If the creature fails the save, they take 1d6 necrotic damage and become Infected for 1 minute. On a successful save, the creature takes half that damage and does not become Infected. Infected creatures produce their own 10 foot miasma, and creatures suffer the effects of overlapping miasma areas. At level 18 all Aura(s) of Miasma's area increase to 30 feet.

To the Core

Starting at 15th level, you have become so overcome with disease that your entire body is septic. Open sores and festering blisters riddle your rotten flesh. You become immune to poison damage and the poisoned condition. 

Additionally, once per turn, when a creature hits you with a melee attack, you splatter a pungent, oily black ichor from your wound. The creature must make a Constitution saving throw against your spell casting DC. On a failed save, the creature takes 2d10 acid damage and becomes Infected for one minute. On a successful save, the creature takes half the acid damage and is not Infected.

Pandemic

At 20th level, you are the Bringer of Plagues, spreading disease like wildfire. Creatures within one of your Aura(s) of Miasma have disadvantage on Constitution saves. In addition, whenever you deal melee damage to a creature, that creature becomes Infected for 1 minute.