Circle of Pollution

Black ooze pools under the feet of a ragged looking women. Her hair is unkempt and messy, and her eyes wild. With a flick of her wrist, the ooze animates into tendrils, any flora they touch withering and rotting away rapidly. Those few druids who follow the tenets of the Circle of Pollution are considered evil and cruel by the rest of druidkind, a bane to nature and to life itself. Rot, and filth is all that a circle of pollution druid can give.

Rotting

2nd-level Circle of Pollution feature

The magical talents you've learnt from nature have become polluted and rotten. Whenever you hit a creature with a spell that deals acid, poison, or necrotic damage, you may choose to inflict a stack of rotting. As an action, you may cause the rot to burst dealing 1d4 acid or necrotic (your choice) damage per stack of rotting expending all stacks of rotting. Only one creature at a time may be affected by rotting, and may have a number of rotting stacks equal to their constitution modifier (minimum of 1). 

If a creature gains more stacks of rotting then their constitution modifier allows, they take 1d6 acid or necrotic (your choice) damage.

At 9th level, the base damage of rotting increases to 1d6 and the excess damage to 1d8, and at 15th level it increases to 1d8 and to 1d10 respectively.

Polluting Aura

3rd-level Circle of Pollution feature

Your connection to pollution allows you to use it in combat as a stench cloud. You may expend a use of wild shape to creating an 15-foot radius aura of stench that follows you. Creatures that start their turn or move into the aura must make a Constitution saving throw. On a failure, they become poisoned for as long as they remain within 15 feet of you. The stench aura lasts for 1 minute, ending early if you are [condition]incapacitated[/condtion] or if you dismiss it as a bonus action.

At 6th level, the range increases to 20 feet, at 12th level, it increases to 25 feet, and at 18th level, it increases to 30 feet

Wilting Touch

6th-level Circle of Pollution feature

Your touch brings rot and pollution, wilting plants and rapidly aging things to dust. You may touch a creature or object as an action. If it is a creature, it must make a constitution saving throw against your spellsave DC. On a failure, you may age it a number of years equal to 10 times your wisdom modifier. On a success, the creature takes 3d10 necrotic damage. Creatures that are immune to being aged magically or the effects of aging automatically succeed the saving throw, but take 6d10 necrotic damage. 

If you target a plant creature or a magical plant, it automatically fails the saving throw and takes 6d10 necrotic damage.

Cause Pollution

10th-level Circle of Pollution feature

Your connection to decay and to rot has grown strong enough to allow you to force the weather to bend to your will. You may spend 10 minutes manipulating the weather. After an hour has passed, one of the following events occurs.

Acid Rain. Every cloud in a 1 mile radius gather and start to rain drops of acid, quickly eroding terrain and building alike. Once per minute, creatures of your choice within 100 feet must make a constitution saving throw, taking 1d4 acid damage on a success, and half that on a failure. You may focus the rain as an action, creating a 15-foot radius 300-foot high cylinder within 60 feet of you. A creature caught in the cylinder must make a dexterity saving throw against your spellsave DC, taking 5d4 acid damage on a failure, and half that on a success. You may maintain and move the cylinder up to 20 feet in any direction as a bonus action on your turn. If you do not use your bonus action to maintain the focused acid rain on your turn, it disperses. You can only focus the acid rain once. The acid rain lasts for 1 hour.

Choking Smog. You release a heavy and toxic smog, that strangles the lungs. Creatures of your choice within 100 feet are considered lightly obscured. Creatures within 30 feet are considered heavily obscured and blinded. As an action, you may cause the fog to swallow a creature within 60 feet of you that you can see. That creature must make a constitution saving throw, taking 4d10 necrotic damage on a failure and half that on a success. Creatures that don't need to breath automatically succeed the saving throw. The smog lasts for 1 hour.

Toxic Water. You cause a nearby freshwater source to become toxic and poisonous. You must be within 10 feet of a river, well, pool, or similar body of water. The water becomes poisoned, causing any creature who drinks or submerges themself in it to become poisoned. Whenever a creature spends a minute in the water or drinks it, it takes 3d8 poison damage and becomes poisoned for 1 hour. The water looks, smells and tastes the same, but detect magic can reveal the effect. The water remains poisonous for 1 day.

Decay

14th-level Circle of Pollution feature

Your very presence is a abhorrent, an affront to nature itself. While you are in nature, the grass you walk upon wilts and the flora around you wilts at your presence. Whenever you deal acid, poison or necrotic damage, you may roll an extra die when rolling for damage. If you roll a 1 on a damage die, you may reroll it and must use the new roll.

Additionally, when you kill a creature, you may cause it to disintegrate. A disintegrated creature and everything it is wearing and carrying, except magic items, are reduced to a pile of fine gray dust. The creature can be restored to life only by means of a true ressurrection or wish spell. You may do this three times per long rest.