Path of Self Sacrifice

You've discovered that in your blood runs ancient power forgotten from time, you gain the ability to manipulate your blood in ways that allow you to hinder others and help your allies in combat while expanding your own health to do that.

Barbaric Endurance

Yours is a path that seeks to obtain power through blood rituals and sacrifice, giving you a high tolerance for pain and injuries. At 3rd level when you adopt this path, your rage starts to give you temporary HP equals half your barbarian level times your CON modifier rounded up, those temporary HP disappear when you leave rage.

Blood Vessel

At 3rd level, when you adopt this path, you gain the ability to channel ancient blood that runs through your veins, once per rage, you can spray your blood in a 5ft radius circle around you, dealing you damage equal to your barbarian level, all creatures in range must make a DEX save, save DC is 10 + your proficiency modifier + your CON modifier, if they fail they are blinded for 3 rounds.

You gain an additional charge of Blood Vessel at 6th, 10th, and 14th levels.

Additionally, whenever you deal a killing blow on a creature you heal for half the damage of the killing blow. On the 10th level you heal for the amount of damage you did on the killing blow instead.

Blood Madness

At 6th level, once per long rest, to use as a bonus action Blood Madness: you drain a quarter of your current HP, rounded up, and you choose 2 damage types from Slashing, piercing and bludgeoning, you gain immunity to those types, this effect lasts for 3 rounds. 

on 14th level, you may use this ability twice per long rest

Blood Bond

At 10th level, you can take damage equals to your barbarian level per ally you use this ability on, your mastery of blood magic has allowed you to channel your blood through others veins, every ally you used this ability on gains the rage property for 30 seconds (5 rounds), with all it's traits and properties as you have it, excluding your abilities. you may extend the duration of this ability by taking damage equal to half your barbarian level rounded up, per two rounds beyond the 5th. when you use this ability, each ally affected by it must make a CON saving throw DC 15, upon failure they are poisoned for the duration, you may end this ability any time.

Brotherhood of Blood

Beginning 14th level, your blood powers allow you and your allies to share your life force.

At 14th level, when one of your allies drops below to 0, as a reaction you may take damage equals to twice your barbarian level, restoring the same amount of HP to the ally. When you drop to 0  HP and there's a willing creature within 20 ft, of you, that creature may take damage equal to twice your barbarian level transferring them to you, you gain the same amount of HP.