Oath of Corrosion

Paladins who swear the Oath of Corrosion embrace decay not as a tragedy, but as an inevitability to be accelerated. Flesh putrefies. Steel rusts. Stone crumbles. Kingdoms collapse. Even the works of gods must eventually disappear.

These paladins are rarely benevolent figures. Many believe that preservation breeds weakness and that things which have outlived their purpose deserve to be reduced to ruin. Immortality, undeath, and unnatural preservation are particularly offensive to their creed, for nothing has the right to escape deterioration forever.

The power of this oath manifests as supernatural corrosion. Divine light becomes hissing acid, wounds blacken and refuse to close, and the world itself begins deteriorating around a Paladin of Corrosion.

Tenets of Corrosion

The exact tenets of the Oath of Corrosion vary, but its Paladins commonly uphold the following principles.

Everything Decays. Nothing is eternal. Flesh, stone, kingdoms, and gods are all subject to the same inevitable end.

Hasten the Inevitable. Don't merely await decay when your hand can accelerate it. Destroy what has outlived its purpose.

Despise Stagnation. Immortality, undeath, and unnatural preservation are denials of an essential truth: everything must eventually change or perish.

Leave Only Ruin. When something must end, end it completely. Don't preserve what deserves to disappear.

Signs of Corrosion

The power wielded by a Paladin of Corrosion rarely leaves its vessel unchanged. As your connection to your oath grows, your appearance might increasingly reflect the decay you embody.

You can choose one or more of the following manifestations or create your own:

• Your blood becomes black, caustic, or strangely viscous.
• Your breath carries faint acrid fumes.
• Metal tarnishes after prolonged contact with your skin.
• Small plants wilt when you linger near them.
• Wounds in your flesh hiss rather than bleed.
• Portions of your skin resemble oxidised metal, necrotic flesh, cracked stone, or peeling paint.
• Your eyes resemble pools of acid or clouded poison.
• Your Divine Smites produce no brilliant holy light. Instead, wounds bubble, blacken, dissolve, or rot.

These manifestations have no mechanical effect unless a feature states otherwise.

Level 3: Oath of Corrosion Spell

Level 3

The magic of your oath ensures you always have certain spells ready. When you reach a Paladin level specified in the Oath of Corrosion Spells table, you thereafter always have the listed spells prepared.

Level 3: Ruination

Level 3

The divine power carried by your strikes manifests as supernatural corrosion rather than cleansing light.

Whenever you cast a Paladin spell that has Smite in its name, you can change any Radiant damage dealt by the spell to Acid or Poison damage. When you deal Acid or Poison damage in this way, the target suffers the corresponding effect below:

Corrode

When your Smite deals Acid damage, the target's physical defences deteriorate. It takes a -1 penalty to AC until the start of your next turn. A creature can't suffer more than one AC penalty from this feature at a time.

Putrefy

When your Smite deals Poison damage, its wounds begin to rot. The target can't regain Hit Points until the start of your next turn.

Corrode Objects

Acid damage dealt by your Paladin spells and Paladin features to unattended nonmagical objects deals maximum damage instead of rolling.

Level 3: Accelerated Decay

Level 3

You can invoke your Channel Divinity to accelerate the deterioration of a creature until even its natural defences begin to fail.

As a Bonus Action, expend one use of your Channel Divinity and choose one creature you can see within 30 feet of yourself. For 1 minute, whenever you deal damage to that creature, any Resistance it has to the triggering damage type provides it no benefit against that damage.

Accelerated Decay ends early if you have the Incapacitated condition or use this feature on another creature.

Level 7: Aura of Erosion

Level 7

Your corruption no longer ends at the edge of your blade. The world itself begins to deteriorate in your presence.

You gain Resistance to Acid and Poison damage. In addition, you emanate an Aura of Erosion, a 10-foot Emanation originating from you, while you don't have the Incapacitated condition. You can suppress or reactivate this aura at any time (no action required).

Unattended nonmagical objects and surfaces within the aura visibly deteriorate. Plants wither, liquids hiss and foul, metal tarnishes, wood rots, and stone pits and crumbles.

Corrosive Wake

When you move across a nonmagical surface while your Aura of Erosion is active, you can cause the spaces you move through to remain corroded until the start of your next turn.

Those spaces are Difficult Terrain for your enemies.

Erode

At the end of each of your turns, you can choose one unattended nonmagical object or section of a nonmagical surface within your Aura of Erosion. It takes Acid damage equal to twice your Paladin level, ignoring its Damage Threshold.

Greater Aura of Erosion

At Paladin level 18, the range of this aura increases to 30 feet.

In addition, hostile creatures within the aura can't gain Temporary Hit Points.

Level 15: Nothing Is Eternal

Level 15

Your body has become a vessel of supernatural decay. Conventional toxins and corrosives can no longer harm you, while even creatures supposedly immune to such forces begin to deteriorate beneath your power.

You gain Immunity to Acid and Poison damage, and you have Immunity to the Poisoned condition. These immunities replace the Resistances granted by Aura of Erosion.

In addition, Acid and Poison damage dealt by your Paladin spells and Paladin features ignores Resistance to those damage types. When such damage would be dealt to a creature with Immunity to Acid or Poison damage, you instead treat that Immunity as Resistance.

Thus, a creature normally immune to your supernatural corrosion can still resist it—but nothing is entirely beyond decay.

Level 20: All Things End

Level 20

You can accelerate corrosion beyond flesh and matter, causing the fundamental protections sustaining a creature to deteriorate.

As a Bonus Action, choose one creature you can see within 30 feet. The creature must make a Constitution saving throw against your spell save DC. On a failed save, the creature suffers Absolute Corrosion for 1 minute. On a successful save, it suffers Absolute Corrosion until the end of your next turn.

While suffering Absolute Corrosion, the creature:

• can't regain Hit Points or gain Temporary Hit Points; and
• can't benefit from Resistance or Immunity to damage.

At the end of each of your turns, a creature suffering Absolute Corrosion can repeat the saving throw, ending the effect on itself on a success.

Once you use All Things End, you can't use it again until you finish a Long Rest.