Caustic (3.5e Prestige Class)

The Caustic
"This burning... I have known nothing but this burning for so long, I want you to know it too."

The warlock's power stems from pacts that their ancestors made in forgotten times. Warlocks nowadays don't even think of the source of their powerful archaic energies and dark invocations. What happens, however, when these ancient infernal powers decide that they want to end this pact? What are the effects of a seizure of power, a power bound to the very blood of the warlock? What happens when these rituals and promises of power are called off? The blood changes. The very blood that the warlock uses to harness their eldritch power corrodes and undergoes a caustic change. It becomes vitriolic, an acid, corroding the very veins of the warlock. This would kill a normal man, but the warlock's granted powers have provided its body with the ability to heal. The body burns, the body wrenches, the body shrieks, but no part of it dissolves. The powers that the elder evils are trying to take back are the very powers keeping the warlock's body from dying, at least for a while, at least until the warlock has given into the pain. These warlocks are called The Caustic, for they will die of the acid, but until they do, they will find a way to use it.

Becoming a Caustic
Characters don't pursue this class. No one pursues banishment by the beings that grant them their powers. This class just happens, though only to warlocks.

Class Features
All of the following are class features of the caustic.

You do not, however, gain any other benefit a character of that class would have gained. If you had more than one invoking class before becoming a caustic, you must decide to which class to add each level for the purpose of determining spells per day, caster level, and spells known.

 (Ex): When a warlock changes into a caustic, his blood begins to become more and more corrosive like acid, until it is nothing but. At 1st level, whenever the caustic is struck by a piercing or slashing weapon, that weapon takes acid damage equal to his caustic level, as the acid from his blood dissolves the metal. If the damage is dealt from a natural weapon, the acid damage is instead dealt to the attacker.

 (Ex): The caustic's blood is a special type of acid that most creatures who are resistant to acid are still harmed by. The caustic may treat all Acid Resistance as his caustic level x 2 fewer than it actually is. His Acid Resistance also increases by 2 every level. The caustic begins to attempt to take advantage of its torture, using the acid against his enemies. He gains the Vitriolic Blast invocation as a bonus invocation at first level as well.

' (Sp):''' At 2nd level, a caustic begins to learn how to use the acid in his body to supplement his power. Whenever the caustic performs a Vitriolic Blast, he may add half of his charisma modifier more dice to the damage roll; also, the acid damage that lingers may now linger for a number of rounds equal to his class level/3 instead of class level/5 like in the description of the invocation. A caustic may not use this with his Acidic Expulsion ability.

' (Sp):''' At 2nd level, a caustic can throw out some of the acid in its body at enemies, relieving it, if just for a moment, its burning pain. Whenever the caustic performs a Vitriolic Blast, he may heal a number of hit points equal to his charisma modifier. A caustic may not use this with his Acidic Embellishment ability.

 (Ex): At 3rd level, the acid coursing through the caustic's veins does irreparable damage to his body, though the infernal powers within keep the caustic relatively alive. The caustic loses 2 points of constitution. The caustic gains Darkvision out to 60 feet. He also gains Immunity to poison, sleep effects, paralysis, stunning, disease, and death effects.

 (Ex): At 4th level, the acid has partially dissolved through the caustic's skin, making it thinner and more prone to bleeding. The caustic's Caustic Blood ability now extends to bludgeoning weapons as well. Whenever the caustic is struck, the attacker takes acid damage equal to half the damage her weapon takes, as blood sprays upon the attacker.

 (Su): The caustic has learned how to withhold some of his body's healing properties to let some acid pool up in the palm of his hand. At-will, anything that the caustic can clench a fist around, he may destroy as a full-round action, including magic rings and amulets. Anything that is too big to be clenched into a fist takes 1d6 acid damage per caustic level. A caustic may try to damage an enemy's weapon or armor by making a successful disarm attempt or touch attack, respectively.

 (Ex): At 5th level, the burning of the acid has permanently damaged the caustic's mind, though the infernal power still keeps the heart beating. He no longer feels the pain; he no longer feels anything, really, but the burning is ever stained across the caustic's memory. The Caustic loses 2 points of constitution. However, he becomes immune to critical hits, nonlethal damage, ability drain, or energy drain and becomes immune to damage to its physical ability scores (Strength, Dexterity, and Constitution), as well as to fatigue and exhaustion effects.

 (Ex): At 5th level, the caustic's acid becomes so corrosive it can dissolve even the sturdiest of material. Any acid damage dealt by the caustic bypasses all Acid Resistance. His acid becomes so potent that it can dissolve barriers made of force as if they were made of magically treated unworked stone.

' (Sp):' At 6th level, the caustic may combine his Acidic Embellishment and Acidic Expulsion when using a vitriolic blast''.

 (Ex): At 7th level, the caustic's body has become so irreparably damaged that he can no longer rely on its sturdiness to keep him alive; he must instead rely on his presence and force of influence to keep him a domineering force. The caustic uses his charisma modifier for anything that would normally use his constitution modifier, such as extra hit points, bonus to fortitude save, etc. etc.

 (Ex): At 7th level, the caustic's body dies, finally taken by the acid. The infernal power, however, keeps the caustic aware and alive inside of it. The Caustic becomes undead, and gains the undead subtype. The caustic drops all his hit dice and replaces them with d12s.

Playing a Caustic
Combat: The caustic plays the same role in combat as his warlock counterpart. He does, however, gain improved abilities in the realm of acid. The ability to dissolve weapons and armor renders a lot of martial characters vulnerable to you. The ability to dissolve force effects is rare and is sure to have its uses. If something needs to be melted, or blasted, or generally all messed up, the caustic is there to do it.

Advancement: Unfortunately, the lack of other warlock prestige classes make advancement limited for a caustic. However, the transcendence to undeath opens up a plethora of feat and prestige class options that would not have been available to warlocks otherwise.

Resources: Caustics are generally shunned by other warlocks, which is saying something, since warlocks are shunned themselves. Other caustics may empathize and help each other, but the caustic may be saddened to find that only his adventuring party is willing to help him out.

Caustics in the World
"I have been banished by powers far greater than you; what makes you think I care what you think?"

Caustics are rare in the world, but where they appear, they are usually hunted and shunned. The slow transition to undead makes caustics an abomination to most people. One is most likely to find Caustics where they would find warlocks, only much rarer. The more vile caustics have been found in graveyards as Liches, amassing undead armies and wreaking havoc. The neutral caustics are just trying to get by, and can be found where a warlock would be in any adventuring party.

NPC Reactions: NPCs retract in disgust and fear at the sight of caustics, and the degradation of their body and pale undead appearance leads to many terrible stories. Mostly, NPCs will react the same way they would to warlocks, with skepticism and fear, but to a more extreme degree.

Caustic Lore
Characters with ranks in Knowledge (arcana) can research caustics to learn more about them. When a character makes a skill check, read or paraphrase the following, including information from lower DCs.