Apocalypse Domain.

Few gods embrace the Apocalypse Domain, yet in times of war, disease, or social upheaval, its Clerics appear at the head of grim cults that proclaim the world's imminent demise. Devotes of the Apocalypse Domain are usually apostates and heretics cast from religious orders for their fanatical conviction to the end of all things.
The exact origin of their divine power confounds the elders of established religions. Sometimes, these Clerics derive their powers from the gods of fate, doom, or change. More often, though, they seem to draw their power from the collective gloom of a population facing disaster. Perhaps the world's demise is truly imminent, and these visionaries have found some way to tap into the apocalypse as it grows near.

Level 1 Features:

Apocalypse Domain Spells.

Each domain has a list of spells—its domain spells—that you gain at the cleric levels noted in the domain description. Once you gain a domain spell, you always have it prepared, and it doesn't count against the number of spells you can prepare each day.
If you have a domain spell that doesn't appear on the cleric spell list, the spell is nonetheless a cleric spell for you.

Visions of Annihilation.

You gain the ability to foretell a creature's doom. As a Bonus Action, choose a creature you can see within 120 feet of yourself. Until the start of your next turn, attack rolls against that creature have Advantage.
You can use this feature a number of times equal to your Intelligence, Wisdom or Charisma modifier (minimum of once). You regain all expended uses when you finish a Long Rest.

Level 2 Feature:

Channel Divinity: Doom Song.

You can use your Channel Divinity to hasten a creature's doom. As a Bonus Action, you can use your Channel Divinity to choose a creature you can see within 120 feet of yourself. For 10 minutes, attack rolls against the creature have their critical hit threshold reduced by 2.

Level 6 Feature:

Channel Divinity: All Will Be Dust.

You can use your Channel Divinity to twist a creature's fate. As a Bonus Action, you can expend one use of your Channel Divinity to choose a creature you can see within 120 feet of yourself. That creature has Disadvantage on the next saving throw it makes against your spells before the end of your next turn.

Level 8 Feature:

Potent Spellcasting.

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

Level 17 Feature:

Life Beyond Death.

When you or an ally within 120 feet of you is about to make a Death Saving Throw, you can expend a spell slot (no action required) to heal the target a number of Hit Points equal to ten times the level of the spell slot expended.