Path of the Blood Drinker

Barbarians who choose this path gain some of the abilities of a vampire. They can use their rage to drain the health of their enemies, impose an aura of fear upon their surroundings, and even command the dead. Upon choosing this path, the Barbarian often changes in their appearance somewhat, their skin become pale and bloodless, and their eyes beginning to turn a dull red. The taste of blood becomes sweet to them, like the smoothest wine. 

Blood Devourer

Starting when you reach 3rd level, you can choose on each of your attacks to convert your extra Rage damage to Hit Points that you regain on a hit. The hit creature does not take the damage, instead you regain Hit Points equal to your Rage Damage. This feature can only be used on Creatures that have blood. Constructs, Elementals, and some Undead are immune to this affect. 

Vampiric Presence

At 6th level your vampiric powers inspire fear in your enemies. When you go into a rage, you force all creatures within 10ft of you to make a Wisdom Saving Throw. The DC equals 10+ Half your Barbarian level. On a failure, affected creatures' speed is reduced by half, and any attacks against you are at disadvantage while they are within 10ft from you, until the beginning of your next turn. 

Like many Vampires, you can exert a certain amount of control over the Undead. If this feature affects an Undead of CR equal to half your Barbarian level, they fall under your control until the end of their next turn. You may choose to command them to attack an enemy, flee, or simply do nothing. Affected Undead cannot be commanded to destroy themselves.

Sanguine Hunger

At 10th level, blood becomes not just sweet, but invigorating to you. If you drink one pint of blood from an enemy you slew, within 1 hour of their death, you gain the following benefits for the next 8 hours: 

• Your rage damage can be applied to your unarmed strikes, and is increased by 1 above it's usual amount for all attacks, including armed attacks. 
• If you do not have it already, you gain darkvision up to 60ft. If you already have darkvision, it increases by an additional 20ft. 
• You have advantage on Survival and Perception checks while it is night time. 

Lord of the Night

At 14th level, your physiology adapts to become ever more vampiric. You gain resistance to Necrotic damage. While raging, you regain 1D6 Hit Points at the end of every turn, unless you take Radiant Damage on that round. However, you are now vulnerable to attacks from Silvered weapons, and your perception checks are at disadvantage while in direct sunlight.