Oath of Blood

While this is an archetype of paladin, it is one of a few subclasses that is referred to as a "Death Knight". These necrotic warriors are the dark side of paladins, reveling in death and darkness, but still following certain oaths and codes, just like their lighter counterparts.

Some death knights find a special affinity for the blood and bone of the living. They carve into their enemies, sustaining themselves with deadly sanguine strikes, while using the bloody, shattered remains of the dead to fortify their own defenses. These crimson-soaked knights bend the very rules of mortality to control the front lines of the battlefield.

Tenets of Blood
A death knight who takes this oath has the following tenets emblazoned in runes on their armor.

Eternal Hunger. You thirst to be surrounded by death and pain, be it that of your enemies or of innocents. Often it is not merely enough that your targets die but they must feel pain.

Waste Not the Spilled. When you have defeated a creature you must use its blood to recharge your unholy magics. If evil must be done let it mean something and be not wasted.

Loyal to the Necropolis. You must obey direct orders from the nearest necropolis's government. If you should find yourself in conflict with the High Lich, you have the moral obligation to slay them and take their place in the hierarchy.

Oath of Blood Spells

 You gain oath spells at the paladin level listed.

Paladin Level	Spells
3rd	Inflict Wounds, False Life
5th	Spiritual Weapon, Prayer of Healing
9th	Vampiric Touch, Life Transference
13th	Mordenkainen's Faithful Hound
17th	Hallow, Synaptic Static

Necrotic Smites

Starting at 3rd level, any radiant ability granted by your base paladin skills now does necrotic damage instead.

Channel Divinity

When you take this oath at 3rd level, you gain the following two channel divinity options.

Mark of Blood. As an action, you can cast Hunter’s Mark on a creature. Additionally, when this creature attacks another creature, its target is treated as if it has resistance to the damage dealt. This effect lasts for an hour or until the creature is more than 100 feet away from you. This effect can be transferred the way Hunter’s Mark is.

Dark Command. As an action, you can create an aura of compelled duel. All enemies within 10 feet have disadvantage on attack rolls against creatures other than you, and must make a Wisdom saving throw each time it attempts to move into a space that is more than 30 feet away from you; if it succeeds on this saving throw, this ability doesn’t restrict the target’s movement for that turn. This lasts for one minute. The ability also ends if you attack any unaffected creature, if you cast a spell that targets a hostile creature that isn’t under this effect, or if a creature friendly to you damages one of the targets or casts a harmful spell on it.

Blood Feast

Starting at 7th level, when an enemy drops to 0 hit points within 15 feet of you, you regain 1d6 HP.

Gorefiend's Grasp

Starting at 15th level, when you Smite, all enemies within 30 feet of you who would be hit by your attack roll are pulled 15 feet closer to you.

Fleshcraft

Starting at 20th level, you gain the ability to modify your flesh and bone, entering a blood rage and gaining natural weapons and other supernatural effects. For the next minute, you gain the following attributes:

• You have advantage on Intimidation checks.
• You gain natural weapons for the duration. Any unarmed strikes you make deal 1d12 slashing damage.
• You have resistance to nonmagical bludgeoning, piercing, and slashing damage.
• When you cause a creature within 15 feet of you to fall to 0 HP, the duration of this ability resets. If there is a medium creature or two small creatures at 0 HP within 15 feet of you when you begin this ability, you also gain the following benefits:
  • You have advantage on Strength saving throws.
  • You are treated as one size larger for purposes of grapple checks.
  • Natural 20 rolls targeting you still deal damage, but do not deal the extra damage or effect from being a critical hit.

This ability can be used once per long rest.