Crimson Knight

The archetypal Crimson Knight combines the martial superiority common to all fighters with the strength of hemomancy. This power is often lying dormant in the knight's own blood, or perhaps is granted as a boon by an otherworldly being who the knight serves or that has taken interest in the knight's future. By manipulating their own life force, Crimson Knights march into battle as terrifying behemoths cutting down all opposition. As a Crimson Knight fighter, you decide the manner through which you acquired your hemomantic powers. Did one of your ancestors make a powerful blood pact that carried through generations? Or did you earn the favor of a being able to awaken your own awareness of the life giving force that is blood? Consult the Crimson Knight Origins table for a possible origin of your power.

The effects of this subclass count as divine in addition to Arcane.

Crimson Knight Origins

d6	Origin
1	You unearthed hidden texts containing instructions on blood arts.
2	One of your ancestors was a powerful blood mage, and the magic has been passed down.
3	You entered a pact with an unseelie archfey that transformed your essence.
4	You were experimented upon by an organization that wanted to create a perfect soldier.
5	You suffered a mortal wound near a place of immense magical power, and it's energies mixed with your blood.
6	A powerful vampire lord has granted you some of its dominion over blood after you earned its favor.

Blood Arts

At 3rd Level, Your own physical fortitude is a wellspring of power, which you learn how to utilize while advancing your understanding of hemomancy and your gift. You learn various blood arts, which are detailed below.
Some of your blood arts expend your Hit Dice, as specified in each art's description, and you can't use an art if it requires you to use a Hit Die when your Hit Dice are all expended. You begin with knowledge of the following blood arts and learn more as you conquer the blessing bestowed upon you.
- Blood Challenge. As a bonus action, you can challenge a creature within 60 feet of you to single combat and expend a Hit Die to tether your essences together. This challenge lasts until the end of your next turn or until you challenge another creature. While challenged, a creature has disadvantage on any attack roll that doesn't target you, and you have disadvantage on any attack roll that doesn't target it.
- Crimson Strike. You can envelop your weapons with hemomantic power. Once per turn, when you hit a creature with a weapon attack, you can expend a number of Hit Dice up to your proficiency bonus to deal necrotic damage to the target, in addition to the weapon’s damage. You roll the Hit Dice, and the extra damage to the target is equal to the number rolled + your Constitution modifier.
- Sense Blood. As an action, you can expend a number of Hit Dice up to your proficiency bonus and gain advantage on Wisdom (Perception) and Wisdom(Survival) checks to track creatures with blood for a number of hours equal to the number of Hit Dice expended. In addition, while this effect is active, you know the exact location of all creatures with blood within 30 feet of you.

With your bolstered fortitude, you regain all expend hit die upon completing a long rest.

Crimson Ward

Also at 3rd level, The gift of hemomancy manifests as a crimson shimmering protective ward around you. The ward has hit points equal to twice your fighter level + your Constitution modifier. Whenever you take damage, the ward takes the damage instead. If this damage reduces the ward to 0 hit points, you take any remaining damage.
While the ward has 0 hit points, it can't absorb damage, but its potency persists. Whenever you expend Hit Dice to use one of your blood arts as described in the Blood Arts feature, the ward regains a number of hit points equal to your Constitution modifier times the number of the expended Hit Dice.
When you finish a long rest the ward is replenished completely, regaining all of its lost hit points.

True Blood Knight

At 7th level, You achieve greater mastery over your gift, enhancing your knightly skill. You learn the following blood arts:
- Blood Knight's Defense. When a creature within 5 feet of you is hit by an attack, you can use your reaction to expend one Hit Die and interpose yourself between the creature and the attack, becoming the attack's target. You roll the Hit Die, and the attack automatically hits you but its damage is reduced by an amount equal to the number rolled.
- Crimson Regeneration. While below half your hit point maximum, you can use a bonus action to expend one Hit Die. You roll the Hit Die and regain a number of hit points equal to the number rolled + your Constitution modifier.

Additionally you may now use Hit die in place of your martial die to execute martial maneuvers.

Sanguine Recovery

At 10th level, You can draw out every last drop of your vitality in the face of an adversary. If you roll initiative and all your Hit Dice are expended, you regain a number of expended Hit Dice equal to your proficiency bonus.

Crimson Bulwark

At 15th level, Your hemomantic abilities have made your body more resilient. You have resistance to bludgeoning, piercing and slashing damage from nonmagical attacks, and your hit point maximum can't be reduced. In addition, you learn the following blood art:
- Blood Knight's Resilience. When you decide to use your Indomitable feature to reroll a saving throw, you can expend one Hit Die, rolling it and adding the result to the new roll for the saving throw.

Crimson Knight Paragon

At 18th level, You have become an exemplar among Crimson Knights, a champion of dedication, endurance and persistence. Your Constitution score increases by 4, as does your maximum for that score. In addition, you learn the following blood art:
- Crimson Champion. When you are reduced to 0 hit points but not killed outright, you can use your reaction to expend a number of Hit Dice equal to your Constitution modifier. You roll the Hit Dice, and immediately regain a number of hit points equal to the number rolled.