Blood Bolt

You channel your life force into a powerful bolt of necrotic energy and hurl it at a creature you can see within range. The bolt draws strength from vitality, amplifying its power at the cost of health. Make a ranged spell attack against the target. On a hit, the target takes 2d8 necrotic damage.

• Sacrifice: As part of casting this spell, you take 3 HP of necrotic damage, If the blood is yours. This damage cannot be reduced or avoided. (Example: cast using a spell slot of 7th level, will require 15HP - this spell cannot be cast without having the desired HP.) 

• At Higher Levels: When cast using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st, and the HP sacrifice increases by +2 HP per additional slot level.