Life Force Caster

Digging deeper into your desire for power, you gain the ability to create additional spell slots at the cost of your own life force. 

• As a bonus action, and using your dormant life force (hit dice), you may create additional spell slots. The more hit die expended, the higher the level of spell slot created (i.e. you could exchange three hit die for a 3rd level spell slot).
  • The created spell slot must be used during the same turn it is created.
•  For every spell slot created above 3rd level, you must make a Constitution saving throw, the DC for which is 10+2 for every spell slot level above 3rd (i.e. a 5th level spell slot would be 10+4 for a save of 14). On a failure, take one point of exhaustion for every level of spell slot received above 3rd. On a success take a single point of exhaustion. 
• As a bonus action, spell slots may also be created using your kinetic life force (current HP). When a spell slot is created in this way, take 1d8 necrotic damage for each level of spell slot created (i.e. for a 4th level spell, take 4d8 necrotic damage). HP lost in this way can only be regained through a long rest, rather than by regeneration, magic, or any other means. Additionally, gain one level of exhaustion. 
  • The created spell slot must be used the same turn it is created.
• Spell slots can only be created at a level you would already normally be able to cast spells (i.e. if you only have access to up to 3rd level spells, you could not create a 4th level spell).