You have made a pact with a magical entity that defiles and corrupts. Your patron is a source of foul blight and toxicity, such as a hag matron or coven, an archpriest of the yuan-ti, a powerful elder ooze, an archfiend of corruption or mutation, a noxious undead that spreads disease, or even a poisonous spirit of nature, such as a gigantic three-headed snake, That Which Rots, or the crocodilian Dragon of the Swamp.

Defilers have clear motivations, yet their methods for reaching their goals are often circuitous and inscrutable to their followers. Defilers are not always evil, but they universally desire to spread their form of corruption, blight, disease, or poison to the world. Some see this as a gift, while others knowingly strive to cause torment.

Expanded Spell List

The Defiler 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.

Defiler Expanded Spells

SPELL LEVEL	SPELL
1st	ray of sickness, Tasha's caustic brew
2nd	blindness/deafness, Melf's acid arrow
3rd	stinking cloud, toxic breath (new)
4th	venom lash (new), vitriolic sphere
5th	cloudkill, noxious geyser (new)

D&D Beyond Note: New homebrew spells must first be added to your collection.

Withering Affliction

Starting at 1st level, your patron grants you the ability to inflict painful maladies. Choose one of acid splash, chill touch, or poison spray. You learn the chosen cantrip as a warlock spell, and it doesn't count against the number of cantrips you can learn as a warlock.

In addition, when you deal acid, necrotic, or poison damage to a creature using a weapon attack or a warlock spell, you can choose to afflict the creature with magical corruption. The target must succeed on a Constitution saving throw against your warlock spell save DC or else become poisoned for 1 minute. While it is poisoned, the target repeats the saving throw at the end of each of its turns, ending the effect on a success, and taking poison damage equal to your proficiency bonus on a failure.

You can only use this feature to poison a creature two times, and you regain all expended uses when you finish a long rest. The number of uses per long rest increases to 3 at 5th level, 4 at 11th level, and 5 at 17th level.

Agent of Corruption

Starting at 6th level, you become attuned to the essence of corruption itself. You gain resistance to acid damage and poison damage, and you have advantage on saving throws made against poison or disease.

In addition, once per turn, when one of your weapon attacks or warlock spells deals acid, necrotic, or poison damage to a creature that is already poisoned, you can increase the damage that creature takes by an amount equal to your Charisma modifier (minimum +1).

Sickening Ward

At 10th level, your patron gifts you with a shield of toxic mist to sicken your attackers. When a creature within 15 feet of you hits you with an attack, you can use your reaction to shroud the attacker in poisonous mist. The attacker rerolls the attack roll and uses the new result. After the attack, it must also succeed on a Constitution saving throw against your warlock spell save DC or else it is poisoned until the end of its next turn.

Once you use this feature, you cannot use it again until you finish a short or long rest.

Tormenting Toxins

At 14th level, you learn how to strengthen the ailments ravaging your foes. When a creature you can see within 30 feet of you makes a saving throw against one of your warlock spells that deals acid, necrotic, or poison damage or causes a creature to gain exhaustion or be blinded, deafened, poisoned, or diseased, if you cast the spell on a previous turn, you can use your reaction to roll 1d8 and subtract the result from the creature's saving throw.

Also, your warlock spells and class features ignore immunity to the poisoned condition and treat immunity to poison damage as only resistance to poison damage. Any creature that otherwise can't be poisoned still has advantage on saving throws against being poisoned by your warlock spells and class features.

New Eldritch Invocations

At 2nd level, a warlock gains the Eldritch Invocations feature. Here are new options for that feature that are available to this subclass.

Venomous Familiar

Prerequisite: Defiler Patron, Pact of the Chain feature
When your familiar hits a creature with a melee attack, you can expend a warlock spell slot to deal 1d12 bonus poison damage to the target for each spell slot level.

Anathema's Ward

Prerequisite: 5th level, Defiler Patron
You learn protection from poison as a warlock spell, and it doesn't count against the number of spells you can learn as a warlock. When you cast the spell, its range is 30 feet, and you don't have to touch the target.

Befoul Food and Drink

Prerequisite: 5th level, Defiler Patron or Hag's Heritage invocation
You learn the new poison food and drink spell as a warlock spell, and it doesn't count against the number of spells you can learn as a warlock.

You can choose to cast the spell without expending a spell slot or requiring material components. Once you do so, you can't do so again until you finish a long rest.

Blighted Blade

Prerequisite: 7th level, Defiler Patron or Hag's Heritage invocation
You can cast the new envenomed weapon spell using a warlock spell slot. Once you use this invocation, you must finish a long rest before you can use it again.

Scent of Corruption

Prerequisite: 9th level, Defiler Patron
You can cast detect poison and disease at-will, without expending a spell slot or requiring components.

Fang of the Malison

Prerequisite: 12th level, Defiler Patron, Pact of the Blade feature
You can create a curved dagger using your Pact of the Blade feature. This weapon deals an extra 1d4 poison damage on a hit. When you hit a creature with it, you can expend a warlock spell slot to deal 1d8 bonus poison damage per spell level to the target and cause it to become poisoned until the start of your next turn.