Blood Fighter

A subclass specialised for the undead player

Class Restrictions

To choose this Fighting Style you must either be a vampire, another type of undead creature, or a being sustained by blood.

Bonus Feature

When choosing this Fighting style, you lose your proficiency with medium and heavy armour, but you gain a +1 to your Constitution score.

Vampirism

At 3rd level, when choosing this subclass, you start regenerating whenever your foes have bled enough. If an enemy creature is within 5 feet of you and its current HP is at or below half of its max HP, you’ll regain 1d4 HP at the start of your turn.

 

(Increase the healing to 1d6 at 5th level, 1d8 at 11th, 1d10 at 16th and 1d12 at 20th)

Blood Magic

Also at 3rd level, you gain the ability to cast the following spells.

Living Armour
Cause Fear
Siphon Life (Learn this spell at 9th level)

Your spell save DC is equal to your 8 + proficiency modifier + your Constitution modifier.

You may use this ability a number of times equal to half your proficiency bonus rounded up, as long as you’re not wearing medium or heavy armour. Regaining all uses at the end of a short or long rest.

Warrior of Carnage

Starting at 7th level, You become empowered by the brutality of the battlefield. Whenever you kill an enemy creature within 5ft of you whilst in combat, you gain +1d4 to all damage you deal with your melee attacks until the end of combat.

This ability stacks up to a number equal to your proficiency modifier.

(At 14th level, increase the damage to 1d6, and 1d8 at 19th)

This ability does not trigger on undead creatures or constructs.

Life Drinker

At 10th level, you may use your action to strike a target creature with a melee attack and force them to make a Constitution saving throw equal to your 10 + your Constitution modifier + your proficiency. On a failed save the target creature suffers 2d6 necrotic damage, and has disadvantage on all strength checks and Strength saving throws until the end of their next turn. You regain HP equal to half the necrotic damage the target suffers.
You may also expend as many Hit Die as you wish, a minimum of 0 and no more than you have Hit Die available, to add 1d6 per Hit Die to the necrotic damage you deal. 
For each Hit Die you expend using this feature, you suffer necrotic damage equal to your Consitution modifier.

If the save is successful, the target only suffers half the necrotic damage, and you regenerate nothing.

You may use this ability a number of times equal to your proficiency modifier, regaining the use after a short or long rest.

Undead creatures and constructs automatically succeed on the save.

Empowered Vampirism

Starting at 15th level, whenever you gain HP from Vampirism, all enemy creatures within 5 feet of you have their max HP reduced and suffer necrotic damage equal to what you gain.

This ability doesn’t work on undead creatures or constructs.

Unquenching Thurst

Starting at 18th level, you no longer suffer any damage from the feature Life Drinker. Also, if you kill a creature using Life Drinker, you permanently increase your max HP by 1d4.