Blood magic

Forbidden by most witch covens, blood magic centers on the use of dark spells and mortal hexes that draw from the spellcaster’s very essence. It is fundamentally more perilous than other witch crafts, but its many risks come with copious rewards.

Blood Magic Bonus Spells
Spell Level Spells
1st hellish rebuke, hollowing curse*
2nd acid arrow, hold person
3rd ruby-eye curse*, vampiric touch
4th blight, dominate beast
5th cloudkill, dominate person

HEX: BLOOD CURSE

Starting when you choose this craft at 3rd level, you can mark a creature with a sinister blood curse. As an action, choose one creature you can see within 60 feet to make a Constitution saving throw. On a failed save, this creature is on the brink of death until the end of your next turn. If the creature at any point in this duration has less than its maximum hit points and has fewer hit points than twice your witch level, it immediately drops to 0 hit points.

NOVICE HEMOMANCY

Also at 3rd level, when you cast a spell which requires material components that do not have a specific cost, you can replace the material components with a drop of blood.

ARCANE BLOODLETTING

Lastly at 3rd level, you can impel your magic with a measure of your own blood. When you cast a spell that has a casting time of 1 action, you can choose to lose 5 hit points to change the casting time to 1 bonus action for this casting.
You can use this feature a number of times equal to your Charisma modifier (a minimum of once). You regain all expended uses when you finish a long rest.

DEATHSEEKER

At 6th level, you can see those near death shrouded in a crimson aura. Even in heavily obscured conditions, you can detect the location of creatures within 60 feet that have less than their maximum hit points. This sense can penetrate most barriers, but it is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt.
Additionally, you have advantage on ability checks you make to track a creature you or your familiar has damaged.

HEMOMANTIC RECOVERY

Beginning at 10th level, you can perform a blood ritual to bolster your magic. Once per day when you finish a short rest, you can spend hit dice to recover expended spell slots. The cost for each spell slot is given on the table below. You can’t use this ability to recover spell slots of 6th level or higher.
Spell Level Hit Dice
1st 2
2nd 3
3rd 5
4th 6
5th 7

SANGUINE

By 14th level, you can wield your own blood like a vicious lash. Once per round, when you cast a spell which deals damage to a creature that is under the effect of your hex, you can choose to lose hit points to increase the amount of damage dealt. For every 5
hit points you lose you can add 2d8 necrotic damage to the damage roll, up to a maximum of 6d8 damage. This feature only applies to a hostile creature which is the sole target of your hex.