Sangromancy

You have unearthed the basics of Sangromancy. Your spellcasting ability score becomes: CON. Your hit die becomes 1D8 as your profane arts fuel your life. You gain the following features.

You can expend hit dice to regain spell slots and you take that much damage in Necrotic damage that cannot be reduced (No action required). You expend twice as many hit dice as the spell’s level to regain that spell slot.

You can expend a spell slot to regain twice as many hit dice as the spell slot’s level as an action.

Due to your constant bloodletting and experiments you gain the Tough Feat.

You can cast the spell Animate Dead on a corpse that has been slain for less than one hour without expending a spell slot. You can use this feature on a corpse that is up to Large in size. You can use this feature once per long rest.

A creature reanimated this way has a Zombie stat block if it is Medium size or Ogre Zombie if it is large size.

You can expend blood to create spell-like effects. You can mimic the following spells by rolling the correlating hit dice and taking the same amount of damage as Necrotic damage that cannot be reduced. The spell is composed of your blood and magical essence and is not affected by spells such as Counterspell or Dispel Magic. A spell mimicked this way deals magical damage as it uses your profane blood that is Bludgeoning, Piercing, or Slashing as is the best fit for the spell.

You cannot mimic a spell more times per long rest than your CON modifier (Minimum 1) for each time you mimic a spell past this you gain one level of Exhaustion one hour later for each instance.

You can cast Dominate Beast or Dominate Person once per long rest without expending a spell slot. The saving throw for the spell becomes STR as you manipulate the blood circulating within. You can force the creature to deal bodily harm to itself or another creature, though the creature gets an additional STR saving throw if you force it to do harm.

Undead and Constructs are Immune to this effect.