Oath of Hate

Paladins who have taken an oath of hate aren’t extremely common, as they were usually paladins of something else first. They aren’t oathbreakers, those that take this oath aren’t just paladins that have broken their vows, those simply tend to lose their powers; they are instead individuals who have purposefully shunned their previous oath after disappointment and betrayal, turning to dark powers to go against everything they once stood for. In turn, whatever light burned in the Paladin's heart has been extinguished, and only darkness remains.

Alternatively, there are also some who have trained extensively to hone their inner darkness, their hatred and penchant for violence and brutality, swearing an oath of darkness to protect others. They are not bound by the rules of kings, gods, or nations, as they act only on their own accord, with no regard to how others may view them. These Paladins are also known as Dark Knights, and they are often seen as outcasts and heretics. Not all of these Dark Knights are evil, but few are truly good.

Note: This works as a revised Oathbreaker, if it ain't clear.

Oath Spells

You gain oath spells at the paladin levels listed.

Spell Level	Spells
1st	bane, hellish rebuke
2nd	hold person, darkness
3rd	animate dead, slow
4th	black tentacles, confusion
5th	contagion, hold monster

Unholy Vestige

Beginning when you first take this oath at 3rd level, your holy powers have been warped by your purposeful quest for darkness. You can use your Lay on Hands feature as a bonus action instead of an action, and whenever you use it and expend points to heal a creature, they only regain 1 hit point instead, gaining the remaining expended points as temporary hit points instead.

Furthermore, your divine smite feature turns unholy and deals necrotic damage instead of radiant. 

Channel Divinity

Also at 3rd level, you gain the two following Channel Divinity options:

Dreadful Aspect. As a bonus action, you channel your darkest emotions and focus them into a burst of magical menace, expending your channel divinity. One creature of your choice within 60 feet of you must make a Wisdom saving throw if it can see you. On a failed save, the target is frightened of you for 1 minute. A creature can repeat the saving throw at the end of its turn.

Black Shield. When you're hit with a weapon attack, you can use your reaction to conjure a shield of black magic, expending your channel divinity. You gain temporary hit points equal to twice your paladin level + your Charisma modifier before the damage is dealt. If you have any temporary hit points remaining, the next time you hit a creature with a weapon attack, you lose the temporary hit points and the attack deals additional necrotic damage equal to the number of temporary hit points you just lost.

Aura of Hate

Starting at 7th level, you gain a bonus to the damage of your melee weapon attacks equal to half your Charisma modifier (rounded up). Any ally gains a +1 bonus to their melee weapon attacks, as long as they are within 10 feet of you. 

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

Dark Wraith

At 15th level, you gain immunity to necrotic damage. In addition, whenever you score a critical hit on an attack or reduce a hostile creature to 0 hit points, you may envelop yourself in shadows and magic, your body partially turning into black mist (no action required).

Until the beginning of your next turn, you gain an additional 15 feet of movement, you gain the benefits of the Disengage action and you can move through solid creatures and objects as if they were difficult terrain. You can’t end your turn inside a creature or an object, being shunted to the nearest unoccupied space and taking force damage equal to twice the number of feet moved this way.

Dread Lord

By the time you’ve reached 20th level, you can, as a bonus action, surround yourself with an aura of gloom that lasts for 1 minute, during which you gain the following benefits:

• You gain the benefits of the darkness spell, as if it was cast on yourself, without needing concentration.
• You can see through magical and nonmagical darkness and dim light as if they were bright light.
• You can use a bonus action on your turn to cause the shadows of the darkness spell to attack one creature. Make a melee spell attack against the target. If the attack hits, the target takes necrotic damage equal to 3d10 + your Charisma modifier.

You can use this feature once, regaining the ability to use it again when you finish a long rest.