Arterial Drain

The basic Sangromantic spell. You rip the blood you crave from your enemies’ veins to sustain yourself. Choose up to 2 creatures you can see within range. If you choose more than 1, they must be within 5 feet of each other. A target must succeed on a Constitution saving throw or take 1d6 necrotic damage; if they are already damaged, instead they take 1d8 on a failed save. You regain lost health equal to half of the total damage dealt by this spell, rounded down. 

This spell’s damage increases by 1d6/1d8 when you reach 5th level (2d6/2d8), 11th level (3d6/3d8), and 17th level (4d6/4d8).