Raphael's Blood Rager Barbarian

With a blood rage that's keeps them in a trance-like state, covered in crimson, their intimidating forces over the very life force that runs through the veins of any living creature makes them one of the most formidable warriors to behold and some of the most unkillable enemies to face.

Blood Rage

Beginning at 3rd level, you can choose to enter a Blood Rage instead of a normal Rage. When you Blood Rage, you lose your resistance to bludgeoning, piercing and slashing damage. Instead, every time you deal you apply your rage damage bonus to a damage roll, you regain a number of hit points equal to your rage damage bonus, rounded down if the damage is resisted. Whenever a creature within 5ft of you has their hit points reduced to 0, while you are Blood Raging, you can choose use your reaction to add their constitution modifier (minimum of 0) to your attack and damage rolls until the end of your next turn. You cannot gain this bonus if the creature is a plant, construct, elemental or undead. 

Pained Demise

At level 6, as part of a successful attack action, you can spend a number of hit die up to equal your constitution modifier and add them to your damage roll. Doing so will end a blood rage, but not a regular rage, and cause you to gain 1 level of exhaustion.

Liquid Vengeance

Beginning at 6th level, if you take any damage before your next turn after using your Reckless Attack feature, you can add half of the amount of hit points you lost to your next damage roll on the following turn. If you miss all your attacks that turn, the damage bonus is lost.

Leeching Critical

Beginning at 10th level, whenever you roll dice to add to your critical damage due to your brutal critical feature, you regain a number of hit points equal to half the damage rolled.

Blood Sense

Also at level 10, you are able to sniff out an injured creature from far away distances by their blood. While raging, you are able to sense the direction and and presence of any creature below half of their maximum hit points out to a range of 30ft times your barbarian level. You can only use this ability if you are able to smell.

Fueled by Blood

Beginning at 14th level, you can use your Pained Demise feature an unlimited number of times. Additionally, every time a creature within 30ft of you is reduced to 0 hit points, you lose a level of exhaustion, if you have no levels of exhaustion when this happens, you instead regain 1 spent hit die up to your maximum.