Ash can have many contradictory qualities. It can be hot or cold, light or dark, an ordered pile in an urn, or a chaotic torrent on the wind. Gods of ash burn away rot and decay but also spread death, famine, and pestilence. The nature and intent of a god of ash can be hard to interpret, and they are often doomed to tragedy or doomed to bring tragedy onto others, and gods of ash often have dual natures. Gods of ash include divine entities of destruction and fire, (such as Garyx, Talos, and Kossuth) and powerful primordial elementals and other extraplanar beings of radiance, fire, or death (such as the Queen of Air and Darkness, Apep and Null). Ash domain clerics will sometimes worship gods of the sun (such as Pelor, Lathander, and Heliod), often seeing visions of the sun in the far future engulfing them and the world they inhabit in a flash of immense power. Clerics of gods of ash are often visited with visions of the destruction of their foes and gods of prophecy (such as the Raven Queen, Beshaba, and Savras) are often the sources of these cleric's visions and destructive powers.

For this homebrew subclass to properly work, you will need to add the homebrew spells 'Annihilating Strike' and 'Ray of Annihilation' to your collection.

Bonus Language

When the cleric chooses this domain at 1st level, they learn one language of their choice between Abyssal, Celestial, or Infernal.

Abyssal

You learn one language of your choice between Abyssal, Celestial, and Infernal.

Celestial

You learn one language of your choice between Abyssal, Celestial, and Infernal.

Infernal

You learn one language of your choice between Abyssal, Celestial, and Infernal.

Blessings of Ash

Also at 1st level, you learn two cantrips that deal fire, necrotic, or radiant damage from any spell list. These cantrips count as cleric spells for you. You may choose to learn cantrips from the cleric spell list instead if you prefer. When you cast a cantrip that normally targets only one creature that deals fire, necrotic, or radiant damage, you may choose to have all creatures within 5 feet of that creature make a Dexterity saving throw (DC = your spell save DC). Creatures effected by this feature take 1d6 damage of the triggering damage type on a failed save and half on a success as a burst of embers, soot, or light explodes from the impact of the spell's energy. This damage increases by 1d6 when you reach 6th level (2d6), 11th level (3d6), and 17th level (4d6).

Channel Divinity: Annihilator's Arms

Starting at 2nd level, you can use your channel divinity to manifest some of the lethal destructive energy of your god through spiritual weapons that emerge from you.

As a bonus action, you summon two spectral, glowing ashen arms from your body. You gain the ability to use your action to take up to two of the following attacks:

Annihilating Strike: Make a melee weapon attack using your spell attack modifier to hit against a target within 5 feet. On hit, the target takes 1d6 fire damage, 1d6 necrotic damage and 1d6 radiant damage. Treat this attack as a cleric cantrip for the purpose of determining extra effects (such as Ashen Burst) and calculating damage (such as Potent Spellcasting). If you deal damage to the target with the attack and the target is a creature, you may force the target to make a Constitution saving throw (DC = your spell save DC) and become cursed on a failed save.

Ray of Annihilation: Make a ranged spell attack using your spell attack modifier to hit, range 120 feet. On hit, the target takes 1d4 fire damage, 1d4 necrotic damage, and 1d4 radiant damage. Treat this attack as a cleric cantrip for the purpose of determining extra effects (such as Ashen Burst) and calculating damage (such as Potent Spellcasting). If you deal damage to the target with the attack and the target is a creature, you may force the target to make a Constitution saving throw (DC = your spell save DC) and become cursed on a failed save.

A cursed creature is affected as if they failed the saving throw for the spell bestow curse cast at 9th level, with one additional available option for the nature of the curse:
A cursed creature gains one level of exhaustion when it is initially cursed. For every 24 hours that passes, the creature must repeat this saving throw or gain another level of exhaustion. Once the curse is removed, all levels of exhaustion the creature has gained from this curse vanish.

The number of attacks you may take with this action increases to three when you reach 11th level in this class and to four when you reach 17th level in this class.

Ashen Warding

Starting at 6th level, you can manifest a whirling cyclone of embers, light, and soot and whip it like a tendril between an attacking enemy and their target. When a creature within 30 feet of you that you can see makes an attack, you can use your reaction to impose disadvantage on the attack roll before it hits or misses. An attacker that can’t be blinded is immune to this feature.

Potent Spellcasting

Starting at 8th level, you add your Wisdom modifier to the damage you deal with any cleric cantrip.

Revelation of Ultimate Entropy

At 17th level, you see an image of an endless darkness at the center of all things, followed by an explosion, then an implosion, then a halcyonian void. With this understanding of energy and entropy, if you would deal fire, force, necrotic, or radiant damage, you may choose to deal one of the other types of damage instead. Additionally, while your Channel Divinity: Annihilator's Arms ability is active, you may use your action and two uses of Channel Divinity to cast one of the following spells: meteor swarm, power word kill, storm of vengeance, or time stop.