Blood Mage - HB class for 5e

This horror-themed class delves deep into the esoteric magic of the physical body, using spells that are cast through the sacrifice of blood or by inflicting harm upon oneself. Their abilities are not for the faint of heart, as their magic is intertwined with the grotesque and gruesome. Blood magic is for those who are drawn to the darker side of magic, whether a monster hunter, dedicated servant of evil, or a practitioner of black magic for their own reasons. 

I found a lack of this particular kind of fantasy in 5e, so I played around and made one! The blood mage is meant to feel like a horror villain in the style of Micheal Myers or Freddy Kruger; beat them down but they continue to pursue. I was also inspired by Bloodbending from Avatar: the Last Airbender. And of course, classic necromancy/lichdom was the third driving force. I feel like the end result is a unique DnD class based around risk and a lack of self-preservation. 

There are not any classes in DnD that primarily use Constitution the way some classes use Dexterity, Wisdom, Intelligence, Strength, or Charisma. I wanted to show good ole' Con' some attention and foun this a compelling way to do so.

If you find any reason to balance this class, please let me know. Currently this is version 1.1, so I imagine there will need to be much improvement.

Start spilling blood.