Filth Patron

Sickness follows life. Some life follows sickness. Disease and poison is inescapable for many scholars and adventurers. Those who have visited Kesdi have returned with a blight on their soul. Whether through corruption or through the maddening whispers, the hosts where relentlessly chased by an ineffable being. 

After being poisoned, you have been one marked by this being. After great struggle, you have made a pact with this being.

Level 3: Filth Spells

The magic of your patron ensures you always have certain spells ready; when you reach a Warlock level specified in the Filth Spells table, you thereafter always have the listed spells prepared.

Filth Spells

Warlock Level	Spells
3	Burning Hands, Ray of Sickness, Protection from Poison, Blindness/Deafness
5	Bestow Curse, Stinking Cloud
7	Vitriolic Sphere, Giant Insect
9	Cloudkill, Insect Plague

Level 3: Miasma

You gain the ability to spread stacks of Miasma. At the beginning of a creature's turn, it takes Xd4 acid damage, where X is equal to the amount of miasma counters on it and creatures within 5 feet. After the creature takes damage from Miasma, it decreases by a stack.

If a creature with a Miasma stack hits another creature, the opposing one makes a Constitution saving throw equal to your spellcasting ability. On a failure, that creature gains Miasma stacks equal to your proficiency bonus. On a success, the creature is unable to get miasma stacks from the attacker for 24 hours.

Whenever you deal hit a creature with an attack, you may use your bonus action to add Miasma stacks equal to your proficiency bonus.

At level 6, Miasma's damage die increases to a d6, a d8 at 10th, a d10 at 14th, and a d12 at 18th.

Level 3: Revolting Aura

You left off a disgusting stench around you. As an action, you may activate or deactivate your Revolting Aura. At the start of each creatures within 10 feet of  you must make a Constitution saving throw equal to your spellcasting ability. On a failure, the creature gains stacks of Miasma equal to your proficiency bonus. On a success, the creature become immune from gaining Miasma stacks from you this way for 24 hours. You may only spread Miasma stacks equal to your warlock level this way. Once you exceed this, your Revolting Aura deactivates and cannot be reactivated until your next short rest.

Level 6: Burrowing Insects

Bug adore you and your patron. You are able to give bugs into others or yourself. You may use this feature equal to your Charisma modifier (Minimum of 1) per Long Rest.

Burrow

As an action, you may have bugs burrow in your skin. When you do, you absorb all Miasma stacks within 15 feet and gain temporary hit points equal to the amount absorbed.

Infest

After hitting a creature, you may use your bonus action to infest bugs into their skin. When you do this, the creature is no longer immune to gaining Miasma stacks.

Delve

As a reaction when a creature hits, you may have bugs delve into a creature's skin. When you do, the creature transfers all stacks of Miasma within 5 feet to the attacked creature.

Level 10: Rotten

You are permanently imbued with stacks of Miasma equal to your proficiency bonus.

Level 14: Putrid Atrophy

Once per turn when you hit a creature, you may use your bonus action to transfer all stacks of Miasma within 30 feet to the hit creature.

Once you use this feature, you can’t use it again until you finish a Long Rest unless you expend a Pact Magic spell slot (no action required) to restore your use of it.