The Plague

You have made a pact with a being of plague and disease, Most of these beings are benign, Only spreading their sickness when needed by the gods. Some however, Are purely malevolent in nature, Wanting to spread their plagues over the planes of existence and corrupt all. Such beings to forge a pact include Elementals. Or some of the more evil creatures, such as Talona, The horseman Pestilence and even Mammon. When making your Warlock, think about what your patron may be aligned to and the possible consequences of that.

(Unlike other Warlock subclasses, Your spellcasting ability is Constitution.)

Expanded Spell List

The Plague 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 Expanded Spells

Spell Level	Spells
1st	fog cloud, bane
2nd	protection from poison, ray of enfeeblement
3rd	slow, stinking cloud
4th	blight, contagion
5th	cloudkill, vitriolic sphere

Disease Expert

Starting at 1st level, You gain immunity to poison and disease. Additionally, you can sense sickness coming off of a creature from 300 feet away. If you sense an illness in this way, you can tell the direction that it is coming from and what illness is afflicting that creature.

Afflicted Host

Starting at 6th level, You've gained mastery over your own contagion. As an action, you can expel your own bile at a target within 30 feet of you, on a hit, the target becomes afflicted. An afflicted creature must make a constitution saving throw against your spell DC or take 5d6 poison damage and vomit copious amounts of blood. If the afflicted creature is hit with poison damage by a spell or weapon attack, you can roll an extra damage dice for it.

Additionally, If you hit the same target twice with this ability, they become contagious, causing any creature they touch (Up to a maximum of 5) to receive the afflicted condition. The maximum afflicted you can have at a time increases when you reach 10th level (10), 14th level (15), and 17th level (20). You can use this feature twice and regain the ability to do so after finishing a short rest.

Toxic Anatomy

Starting at 10th level, your blood has become caustic to outside sources,  Any nonmagical weapon made of metal that hits you corrodes. After dealing damage, the weapon takes a permanent and cumulative −1 penalty to damage rolls. If its penalty drops to −5, the weapon is destroyed. Nonmagical ammunition that hits you is destroyed after dealing damage. Your blood can eat through 2-inch-thick, nonmagical metal in 1 round.

Additionally, As an action you can choose to launch your corrosive blood at a target within 60 feet, causing their skin to burn. On a hit, the target suffers 3d8 acid damage and must make a constitution saving throw or become Contagious. You can use this action twice and regain the ability to do so after a long rest.

Plague Incarnate

Starting at 14th level, you have become infested by the worst plagues known to mortal kind. Choose a plague to become infested with.

Abyssal Frenzy

You have become infested with the madness of the abyss. As an action, you can touch a creature within 5 feet and cause them to become infected, If you are in combat with the target you must make a melee spell attack. After a set period of time, the target becomes Frenzied and starts attacking every living thing in sight (Other then you) for an hour and becomes Contagious, any creature that is hit by the target becomes Frenzied  immediately and Contagious (Up to a maximum of 5).  If the creature is CR 5 or lower it dies of a heart attack once the effect ends. You can set the activation delay up to a month and you can end the effect at will.

Additionally, You gain immunity to Exhaustion.

You can use this action once and regain the ability to do so at dawn. You gain more uses when you reach 17th level (2), and 20th level (3).

Devil's Curse

You have been infested with the devil's curse, an illness that causes internal organ failure in it's victims. As an action, you can touch a creature within 5 feet to infect, If you are fighting the target make a melee spell attack roll. An infected CR 5 or lower individual will have one of their organs fail and die within 1d10 days, while a creature above CR 5 will progressively take 10d12 poison damage over the course of 1d10 days.

Any creature that has been infected will also become Contagious. Anybody that has direct contact with an infected creature is immediately infected themselves (Maximum of 50 total infected per day). You can also shield others from the devil's curse, It can be specific or it can be general such as "All the townsfolk" or "Everyone except the bandits". Also, you can use this ability on other things to poison such as the water supply, a corpse to make a trap or on a CR 5 creature a second time, to make them take the leftover damage immediately.

Additionally, you gain immunity to acid damage.

You can use this action once and regain the ability to do so at dawn. You gain more uses when you reach 17th level (2), and 20th level (3).

Raxius Spore

You have been infested with the Raxius Spore, A spore created by a bacterium from the far realm. As an action, you can turn a target into an aberration from the far realm for an hour. You can choose an aberration with a CR that equals half of your level or lower, If the creature is willing, the change is surprisingly pleasant, If a creature is unwilling they must make a charisma saving throw against your spell DC or be subjected through an excruciating transformation. Whilst an unwilling creature is transformed, They will follow your every whim and live only to serve you. They have the normal stats of the chosen creature and if they are killed in their new form they will revert back to their original form with the same hit points they had before the transformation.

Additionally, you gain immunity to psychic damage.

You can use this action once and regain the ability to do so at dawn. You gain more uses when you reach 17th level (2).