School of Hemomancy

From the religious and shamanic practices of ages past to the medical theories of current times and the arcane investigations into the secrets of universal life and death energies, blood has always played a part. Mages of all traditions recognised that there is something latent and sacred in the crimson fluid that sustains life. To let it course is to nourish life but to see it spilled is to be reminded of mortality. This dichotomy of blood has always intrigued scholars but few dare to wield with such magic.
Others gave in to their macabre curiosity and began experimenting with extracting energies from the blood of living creatures. Built on the foundation of Necromancy and Transmutation, Hemomancy is the magic of blood, flesh, and the manipulation of life forces. Hemomancers use this crimson art to bolster their spells to new heights, enforcing their will upon their enemies and empower their own body. Not all Hemomancers are malicious. Some use it to protect their allies from harm and cleanses any ailments affecting their bodies.
Regardless of how one walks this path, Hemomancers would often practice their craft in secrets away from cities, major religious temples and established arcane research institutes as the manipulation of blood is considered taboo across many cultures. Many Hemomancers turn to the life of adventure, travelling the world with trusted allies, constantly experimenting and honing their sanguine craft.

Crimson Reservoir

When you choose this arcane tradition at 2nd level, you can extract the life essence from other creatures to amplify the potency of your spells. You gain a vessel to store life essence (you determine its appearance).

When you damage a creature that is not undead or construct with a wizard spell, you collect the life essence from their spilled blood and gain 1 Blood point per 5 damage dealt. Blood points last for 1 minute. Your Blood points maximum is equal to twice your Proficiency bonus.

When you cast a wizard spell of 1st level or higher, you can expend Blood points equal to the spell’s level to apply one of these effects:

• Reroll the damage dice up to your Intelligence modifier (minimum one) (you must use the new rolls)
• If you force a creature to make a saving throw, it has Disadvantage on the first saving throw this turn. 

Spells that are augmented by Crimson Reservoir do not grant Blood points.

Thicker than water

At 2nd level, you learn to imbue the blood that courses through your veins with magic, fortifying your body. You gain proficiency in Medicine if you don’t already have. You can add your Intelligence modifier to your Constitution saving throws a number of times equal to your Profiency bonus per long rest. 

Blood for Blood

At 6th level, you can entwine your life essence with another creature, bolstering its capabilities. Once per long rest, as an action, you can touch a willing creature with blood and form a blood bond with it for 1 hour, granting both you and the bonded creature temporary hit points equal to 1d4 + your wizard level. When the bonded creature is within 10 feet of you, it can choose to use your Intelligence modifier instead of any of its modifiers when making a skill check. You always know the direction of where your bonded creature is within 1 mile.

Additionally, while the bond is active, you can choose to either see or hear through the bonded creature’s senses for a number of minutes equal to your Intelligence modifier (minimum 1 minute). During this time, you are blinded or deafened (respectively) with regard to your own senses. The bond is broken when either you or the bonded creature is incapacitated or unconscious.

Glyph of Hemorrhaging

Starting at 10th level, as a bonus action, you can expend 2 Blood points and curse a creature for 1 minute. While cursed in this way, whenever the creature takes damage from another creature, it takes an extra 1d8 necrotic damage. At the end of each of the creature’s turns, it can make a Constitution saving throw against your spell save DC, ending the curse on a success. A cursed creature below its half maximum hit points has disadvantage on this saving throw.

This feature cannot be used against creatures that are undead or constructs. Once you use this feature, you can’t use it again until you finish a short or long rest.

Arcane Vampirism

Your mastery of hemomancy allows you to surpass the physical limits of magic. At 14th level, you can siphon your Crimson Reservoir to fuel your spells. As a bonus action, you can consume Blood points equal to half your wizard level (rounded down) to regain spell slots. The spell slots must have a combined level that is equal to the number of expended Blood points and the spell slots cannot be 6th level or higher. Spell slots gained by this feature disappear after 1 minute if it hasn't been used. 

For example, if you’re a 14th-level wizard, you can recover up to seven levels of spell slots — a 5th-level slot and one 2nd-level slot, a 4th-level slot and a 2nd-level slot and a 1st-level slot or two 3rd-level slots and one 1st-level slot.

You can use this feature twice per long rest. At 17th level, you can use this feature three times per long rest.