Path of the sanguine pact

in growing in power, you have found a way to use your own blood as fuel for your strength and the strength of others, regardless of the cost to yourself.

Spellcasting (lvl 3)

you get the eldritch mind eldritch evocation. you have learned to cast spells.

cantrips. you know three cantrips: spare the dying and two other cantrips of your choice from the warlock spell list. when you gain a barbarian level, you can replace one of your cantrips (except spare the dying), with another warlock cantrip of your choice. when you reach barbarian level 10, you learn another warlock cantrip of your choice.

prepared spells. you regain all expended spell slots on a long rest. the number of spells on your list increases as you gain barbarian levels as shown in the prepared spells column of the spellcasting table. chosen spells must be of a level for which you have spell slots. whenever you gain a barbarian level, you can replace one spell on your list with another warlock spell for which you have spell slots.

spellcasting ability and focus. constitution is your spellcasting ability for your warlock spells, you can use any two-handed or versatile weapon (so long as it is held in both hands) or shield as a spellcasting focus for your warlock spells.

Level 3: Blood magic (lvl 3)

you get the lessons of the first ones eldritch evocation. while raging, you can expend one hit die to do one of 2 things; as a bonus action, you can expend a hit die and heal and ally of your choice for your hit die (1d12) + your consitution modifier, in turn, you take damage equal to the rolled hit die (1d12). Or, as a bonus action, you can expend a hit die and add the hit die (1d12) + your constitution modifier as damage to any cantrip, level 1 spell, unarmed strike or natural weapon attack, in turn, you take damage equal to the rolled hit die (1D12). 

your number of hit die is equal to (2x your barbarian level) + your constitution modifier. when casting a spell, you can expend a hit die in place of a spell slot a number of times equal to your proficiency bonus between long rests. if your rage will end this turn or next, as a reaction, you can expend a hit die to keep your rage when you would lose it.

Level 6: Bloodletting (lvl 6)

you get the fiendish vigor eldritch evocation. while bloodied (below half health), the blood hardens into makeshift armor, adding your proficency bonus to your armor class, if you heal by any means above half your maximum health, the bonus goes away (not counting temporary health). every turn while you are bloodied (below half health), at the beginning of your turn, you passively heal for a mount equal to your constitution modifier, you cannot heal above half your maximum health with this feature and healing above half your maximum health removes this effect (not counting temporary health) and cannot heal your character when reduced to 0hp (death saves or stabilized).

while raging or bloodied, you can add your proficiency bonus to your rage bonus damage on any unarmed strikes or natural weapon attacks, even if the attack misses, you can deal damage equal to the bonus damage (rage bonus + proficiency damage), the damage type is the same type as the intended attack and the damage can only be increased by increasing the bonuses (rage bonus, proficiency bonus). unarmed stikes and natural weapons now have the sap weapon mastery.

Level 10: Predator (lvl 10)

you get the lifedrinker eldritch evocation and can use it with whatever you are using as your spellcasting focus. when you hit a creature using the lifedrinker evocation, you can inflict the creature with a level of exhaustion and they have their strength reduced by 1d4, this can be done only once per round of turns.

while raging or bloodied, you gain the ability to sprout tendrils made of your own blood from your body. when you make the attack action, you can target a creature within 15ft of you, the targeted creature is pulled 10ft towards you if possible and then must do a strength saving throw (8 + constitution modifier + proficiency bonus). on a success, the target in inflicted with bleeding (1d4 damage at start of turn) for 2 turns, on a failure, the creature is grappled by you (restrained condition) and inflicted with bleeding until they free themselves through another saving throw, after freeing themselves they will still have 1 turn of bleeding, this can be done a number of times equal to your proficiency bonus per long rest.

Level 14: undying ritual (lvl 14)

your number of hit die is now equal to 3x your level. you can attack using a bonus action instead of an action when using unarmed strike, natural weapon or magic melee attacks, when you do you can inflict a level of exhaustion on the creature and if the creature can be, inflicted with bleeding for 2 turns. if the target is already bleeding, attacks with unarmed strikes and natural weapons are always critical (double dice) if they hit.

As a action, while raging you can expend 10 of your hit die, when you do this your characters health drops to half their maximum (keeping the maximum the same) and cannot be healed above/past half maximum health, in turn, you gain temporary hit points equal to half your maximum health and the amount of health recovered every turn from 'bloodletting' feature is increased to (2x constitution modifier). when an ally is within 10ft of your character, at the start of your turn, they are healed for an amount equal to your constitution modifier. if your character is reduced to 0hp, you can continue to take turns and do actions (action, bonus action, reaction) while on death saves or stabilized, and your armor class increase from 'bloodletting' feature is increased to 2x proficiency bonus while on death saves, returning to normal (proficiency bonus) when stablized or healed. the ritual persists until your character dies, is incapacitated, does a short or long rest or until their rage ends (whichever comes first).