Blood Knight

An unstoppable juggernaut who never wavers, a vampiric warrior dancing between foes, or a dark guardian corrupting the sanguine fuel of life; the Blood Knight manipulates and corrupts the blood of their foes to sustain themselves in endless combat. 

Whether by studying dark magics in Faerun, ancient lore of the Raven Queen in Exandria, or even the tales of mighty undead Knights, these fighters have learned to manipulate the blood of their foes, and themselves, empowering themselves with every single drop of blood spilt. With a heavy emphasis on guarding themselves and allies, these frontlining knights hold the line against everything that dares stand to them, and holds back a tide of foes, often reversing charges into routs as their whirling blades devour their enemies. 

Those that become Blood Knights do so knowing that they are often feared or misunderstood, their powers seen similar to those of Vampires, and quite frankly are. They are multifarious in origin, though all obey a similar call: to march relentlessly against their foes, to protect whom they wish, and to drink the life of those they deem deserving. 

Blood Drinker

The raw power of spilt blood courses through you, giving you a semblance of vampirism. Harming enemies, you siphon their energy into your weapon, healing you. Whenever you make a melee attack against a creature with blood, you heal for half of the damage done, rounded down. You can use this feature a number of times equal to your Constitution modifier (a minimum of once). You regain all expended uses on a long rest.

Unstoppable

Starting at 3rd level, your ashen stamina becomes unparalleled, and your determination to slay your enemy becomes unmatched. As you embrace death, it graces you. While within 20 feet of an enemy who does not have full health, your movement speed cannot be reduced, and you are immune to the Prone and Restrained conditions. You lose this immunity if you do not approach the foe during your next turn. You are not immune to hard control, such as paralysis or similar effects, but are not slowed by difficult terrain, or spells such as Ray of Frost.

Guardian's Sacrifice

Your power over blood extends to your own, offering a guarding ward in return for some of your own vitality. If you or a creature you can see within 15 feet of you is hit with an attack, you may roll 1d8 as a reaction as a dark tendril of your own blood recoils out to protect it.. Roll the die, and add the number rolled to the target's AC against the attack. If the attack still hits, the target has resistance to the attack's damage. You also take damage equal to the 1d8 rolled.

You can use this feature a number of times equal to your Constitution modifier (minimum of once), and you regain all expended uses of it when you finish a long rest.

Deathstrike

Starting at 10th level, you have learned how to inflict the most crushing types of blows: a Deathstrike. You may, in place of making more attacks, push all your might into one grand attack. For every attack you would sacrifice, you gain another damage die of your weapon, and another ability modifier gets added to the damage. If you chose to Deathstrike, you must sacrifice every attack available, not one or two of your maximum of four. 

For example, if you get 4 attacks when you take the attack action, as a Fighter does at 20th level, and you wield a Greataxe with a Strength modifier of +5, you instead would deal 4d12+20, but have only one attack.

Sanguine Ground

The decay of your foes brings life to you and your allies. Whenever you are healed magically, you may expend one of your hit dice to heal that amount + your constitution modifier. Whenever you do this, you may spend a bonus action to share this healing in an aura of 10 feet around you, healing targets of your choice (up to your Constitution modifier) for half of the amount healed. 

Bloodstorm

The desire to bleed your foes overwhelms you for a moment, and succumbing to it unleashes a flurry of strikes against everything in sight. Starting at 18th level, once per long rest, you may whirl around, making one weapon attack at advantage at every foe within 5 feet of you. When you do this, you are unable to move until the end of your next turn, and each opponent struck activates Blood Drinker without expending charges. Enemies attacking you also get advantage until the end of your next turn.