Hemomancer

Blood magic is feared and hated in a similar aspect to necromancers. They can sacrifice their own blood to fuel their magics beyond the limitations of a normal wizard. Those who are masters in the sanguine rituals know how to use the blood of others, willing or not, to fuel their magics for them. Practitioners of Hemomancy, for one reason or another, have found their way down this dark path and through study of it unlock the mysteries of the power if offers. Though it is taboo, many who are familiar with the arcane know of the power held within the life force of blood. Perhaps the wizard found themselves set upon this path by spilling their blood in a moment of dire need. Conceivably there are arcane users of more nefarious motivations who seek to increase their capabilities at the expense of others, or to shortcut their way to greatness. The study of Hemomancy doesn't make one evil intrinsically, yet many who desire knowledge of it find themselves drawn towards malevolent behavior to further their goals.

Blood for Magic

As an action or bonus action on your turn, you may inflict a wound upon yourself to restore or add a spell slot of a level you are capable of casting. Most hemonancers have a personal ritual dagger they use to perform this rite that is practiced with and has subtle designs to help them control the precision of their wound, though any dagger or object may be used if circumstances demand. The damage inflicted is 1d4 per level of the spell slot when using their ritual dagger. When using anything else the damage increases to 1d4+2 per level of the spell slot. The damage you take as part of this feature ignores temporary hit points, resistances, immunities, and cannot be mitigated in any way, though it can be shared by means of bonding wards etc. This damage does not require you to make a Constitution saving throw to maintain your concentration. The maximum amount of added spell slots you can have beyond the amount on the wizard spell table is equal to your intelligence modifier.

Thicker than Water

You may use a dagger as your arcane focus after it has been impregnated with blood from by the Blood for Magic feature. This effect lasts for 8 hours before the dagger loses this power and must be reunited with blood. 

You also gain 2 additional hp per hit die used to heal on a short rest as you learn to tend to and recover quickly from your wounds.

Crimson Exchange

At wizard level 6 when you use Blood for Magic, you may instead make a melee weapon attack with a dagger against a living creature that has blood. The dagger does normal damage plus half your wizard level (rounded down), and this damage can be subtracted from the damage you would take using the Blood for Magic on this turn. If you miss your attack you do not expend a use of this ability; however, the action or bonus action you used to perform the attack can't be used to perform Blood for Magic. You may use this ability a number of times equal to your proficiency. All uses of this are regained after a long rest. 

Blood Empowered Spells

When you use your Crimson Exchange on a creature you may force the creature to make a constitution saving throw against your spell save DC. If the creature fails this save it loses all resistance to your spells and damage done by your spells for 1 minute. If the creature succeeds it is immune to this ability for 24 hours.

Paid with Blood

At 14th level you may use your blood as the material component for any spell you cast. If the spell component has a gold cost you may pay it at a rate of 1 hit point per 10 gold.