Blood Bolt

You manifest and coagulate a portion of your blood from an open wounds you take 2 points of damage. Make a ranged spell attack against the target. On a hit, the target takes 1d6 force damage. 
If you kill an enemy with the attack you regain 1d4 Hit Points.

This spell's damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).