Through purpose, accident, or experiment; you were born or infused with the blood of an otherworldly being. Either a celestial or fiend has their power flowing through your veins that becomes awakened when you take this subclass. A Fiend or Celestial Knight (F/C Knight) will register as “celestial” or "fiend" depending on the origin of their blood, to any being with an ability to detect such traits. (ex. Sense Good/Evil)

 

Blood Points/Blood Bond/Fury

Blood Points:

Starting at 3rd level, you can start to harness the power of the otherworldly blood inside you. Your access to this power is represented by a number of Blood Points. Your C/F Knight level + Con. modifier determines the number of Blood Points you have access to. These Blood Points allow you to perform certain acts that go beyond a normal being's capabilities. Spending these points is a free action, unless specifically stated otherwise. All Blood Points spent will refresh after a short rest.

Blood Point Abilities:

Peer Into Shadows - Spending 1BP as a bonus action, to grant yourself Darkvision, for 8 hours.

Eye for Weakness - Spending 1BP as a bonus action, to gain advantage on all attack rolls until the end of the current turn.

Blood Bond:

Also starting at 3rd level, the otherworldly blood in your body grants you a blood ritual that creates an otherworldly bond between yourself and a weapon.

You perform the ritual over the course of 1 hour, which can be done during a short rest. The weapon must be within your reach throughout the ritual, at the conclusion of which you touch your blood to the weapon and forge the bond. A bonded weapon is considered magical for the purposes of overcoming resistances.

(During the blood ritual you may include ammo for any ranged weapon you are bonding, to grant the benefit of overcoming magical resistances, but they may only be fired with a bonded weapon. 20 pieces of ammo may be converted in the span of 1 hour, with this ritual. Ammo does not count towards your maximum bonds.)

Once you have bonded a weapon to yourself, you can't be disarmed of that weapon unless you are incapacitated. If it is on the same plane of existence, you can summon that weapon as a bonus action on your turn, causing it to teleport instantly to your hand.

You can have up to two bonded weapons, but can summon only one at a time with your bonus action. If you attempt to bond with a third weapon, you must break the bond with one of the other two.

Blood Point Ability: Fury (F/C Knight 5th Level)

At 5th level, spending BP on a successful attack allows you to add an additional 1d6 damage dice to the damage roll, per BP spent. The damage is Necrotic or Radiant, depending on the origin of your blood. (ie. Necrotic for Fiend origin, Radiant for Celestial.) As your F/C Knight level increases, you can spend more BP to increase the damage. 

Fury Damage Chart:

Level 5 - 8 = Max. 1BP (1d6)

Level 9 - 12 = Max. 2BP (2d6)

Level 13 - 16 = Max. 3BP (3d6)

Level 17 - 20 = Max. 4BP (4d6)

Inflicted Weakness

Blood Point Ability: Inflicted Weakness

At 7th level, when you hit an enemy with a weapon attack, you can spend 1 BP to attempt stunning the target. The target must succeed on a Constitution saving throw or be Stunned until the end of your next turn. (DC: 8 + Con. Modifier + Prof. Bonus)

 

Marked for Execution

Blood Point Ability: Marked for Execution

At 10th level, when you hit an enemy with a weapon attack, you may spend 1 BP as a bonus action, to mark the target. The mark lasts for 1 hour and the target of the mark takes extra damage from your attacks, equal to your Con. modifier. You are also aware of the target’s direction, for the duration of the mark, as long as they are on the same plane as you.

The duration of the mark increases with your F/C Knight level; to 8 hours at 13th level, 24 hours at 16th level, and indefinitely at 19th level. The mark is removed if you slay the target, mark another target, or you choose to end the mark. The mark may be removed with a “Remove Curse” spell, with an arcane roll against your Knight level.

Improved Blood Bond

Improved Blood Bond:

At 15th level, your Blood Bond ritual now grants the bonded weapon an additional 1d6 damage, on successful attacks. Radiant or necrotic damage, depending on the origin of your blood.

Adaptable Resistance

Blood Point Ability: Adaptable Resistance

At 18th level, as a reaction, you may spend 1 BP when hit by a damaging spell or fail a saving throw against damaging magic, to become resistant to that type of damage until your next turn.