Breath of Undeath

As an action, you breath forth a dark mist that surrounds your foes and drain their essence, invigorating you in turn. the target must make a Constitution saving throw with a DC of 8 + your Proficiency Bonus + your spellcasting modifier or take 2d8 Necrotic Damage or half the damage on a successful. You heal yourself for half of the dice roll.

At higher levels. when you cast this spell using a higher spell slot of 3rd or higher, the damage increases by 1d8 for each slot above 2nd level.