Blood Mage

Blood Magic
Beginning at 8th level, you can fuel your magic with the precious nectar of your own body, sacrificing vitality for eldritch might. Whenever you take 5 or more damage (not counting damage dealt to temporary hit points), you gain a Blood Point. When you cast a spell, you can expend these points to fuel the following effects. Additionally, as a bonus action while you are wielding a weapon that deals slashing or piercing damage, you can deal 5 damage to yourself. You can store up to ten blood points at once, and all blood points vanish when you take a long rest.
 * Sanguine Wrath: When you deal damage with a spell, you can spend 1 blood point to increase that damage by 1d6. For each blood point spent beyond the first, this damage increases by an additional 1d6.
 * Bloodshaping: By expending blood points equal to the level of a spell you know, you can cast it without expending a spell slot. Unlike normal warlock spells, this blood spell is not automatically heightened to the maximum slot level available to you. You must pay blood points for a higher level slot if you wish to cast a spell in this manner at a level higher than the default.
 * Power of Pain: When you take damage that would force you to make a concentration check, you can expend 1 blood point for every 15 points of damage sustained (rounded down, to a minimum of 1 blood point) in order to automatically succeed at that check.
 * Cursed Blood: By expending 2 blood points for every level of the cast spell (or 1 blood point if it is a cantrip), you can gain Advantage on any spell attack rolls made by that spell, or inflict Disadvantage on the first saving throw made by one creature against it.

Arcane Flesh
Beginning at 13th level, arcane power suffuses your very flesh, giving you an unnatural vitality far beyond what your physical form would suggest. Your maximum hit point total increases by an amount equal to your class level. Additionally, you gain resistance to necrotic damage, and heal yourself for 10 HP whenever you expend one of your spell slots.

Master of Blood
Beginning at 18th level, your mastery of blood does not halt at the confines of your own flesh. At the end of each of your turns, if you have taken damage since the end of your last turn, you gain 1 blood point for every creature (excluding yourself) within 60' that is alive and below 50% of its maximum health.