The Plague Bringer

You make a pact with a entity of poison and disease. Spread, infest, and corrupt the planes and bring a message to the gods that even they may fall to the terrors of this Plague. You may have made a contact in a cult or fall victim to one of the entities own diseases that lead you down this path. You might follows gods like, Talona or Kiputytto or demons like Juiblex or Obox-ob.

Expanded Spell List

The Plague Bringer lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Plague Bringer Expanded Spells

Spell Level	Spells
1st	purify food and drink, detect poison and disease
2nd	blindness/deafness, acid arrow
3rd	bestow curse, slow
4th	confusion, phantasmal killer
5th	contagion, insect plague

Infected Blood

Starting at 1st level, you gain the ability to imbue your attacks with your entities disease or curse using your blood (or internal fluid) as a base. Once per turn, you can expend one of your hit dice to deal extra damage to one creature you hit with an attack (melee; ranged; or any single target damaging spells). This damage is poison damage.

Because of bonded nature with poisons, you have resistance to poison damage.

Disease Conduit

Starting at 6th level, you fully become a host to your patrons' disease. Anytime you take damage from an attack all creatures within 5ft of you takes your level in poison damage.

Your blood (or internal fluid) can be used to create a number of poison vial equal to your proficiency bonus. Each creation requires you to have a container to hold your blood and takes 1 hour to create them all. These vials act as Poison, Basic (vial) except with the addition effect that if consumed the target must succeed on Con Save using your spell save dc or become diseased and take the poisoned condition for 12 hours. These poison vials expire after 24 hours.

You also become immune to disease.

Contamination

Starting at 10th level, you may bestow your patrons' disease onto others when you use your Infected Blood attack. A creature immune to poison or disease will not be affected with this ability, and any spell or effect that cures diseases will nullify this ability.  You may infuse any of these Diseases into your attack:

Decompose. Target makes a Constitution saving throw if they fail they get the Decompose disease. While under the effects of Decompose the target's body spasms and becomes weaker and sickly while they are diseased. The target takes a 1d4 penalty to each weapon attack it makes. Also, while under the effects of Decompose the target has disadvantage on Dexterity checks and saves.  At the end of each of its turns, the target can make a Constitution saving throw. On a success, the disease fades. If you hit a target with Decompose and choose this affect again, the target has disadvantage on all weapon attacks it makes until the end of your next turn.

Fragmentation. Target makes a Intelligence saving throw if they fail they get the Fragmentation disease. While under the effects of Fragmentation the target's mind starts to become clouded with an intense pain. Whenever the target cast a spell or magical affect, they take your level as psychic damage. Also, while under the effects of fragmentation the target has disadvantage on con checks and saves. At the end of each of its turns, the target can make a Intelligence saving throw. On a success, the disease fades. If you hit a target with Fragmentation and choose this affect again, the target becomes stunned until the end of your next turn. 

Blisters. Target make a Dexterity saving throw if they fail, they get the Blisters disease. While under the effects of Blisters, the target grows poisonous blisters all over the body, causing extreme discomfort and pain. Whenever the target takes damage from any attack, they take an addition 1d8 poison damage (this damage is not calculated for a crit). At the end of each of its turns, the target can make a Constitution saving throw. On a success, the disease fades. If you hit a target with Blister and choose this effect again, creatures within 5ft of this creature takes 1d8 damage and must make a save against the Blisters disease or be infected. 

 

Pestilence

At 14th level, you gain the ability to infect a creature with a powerful disease. When a single target become poised by one of your spells, abilities or affected by one of your Contamination diseases and  they are within your sight, you can additionally affect them with the Pestilence disease. This creature has the Pestilence disease until they cure the disease, or you use this ability again.

After one hour of being infected, while still under the Pestilence disease the target has the poised condition, but do not feel sick or realize they are, with the only symptoms being equivalent to a cold and anyone who attempts to determine if they are need to make a medicine check using your save dc.

After 24 hours the target makes another Constitution saving throw, if they fail the disease infects the target further, if they succeed, they will make this check after another 24 hours. They start to sweat more and have intense headaches; a long rest now only recovers half their hit points. 

After a week they make another Constitution Saving throw if they fail the disease infects the target further, if they succeed, they will make this check after another 24 hours. Any spell or equivalent effect lower than 6th level can no longer cure this disease. They look pale, and everyday has one of the effects of the Contagion spell randomly. At this point it is now clear that the target is sick.

After a month the target makes another Constitution saving throw if they fail the target dies.