You summon a green energy weapon (ranged or throwing weapon) of your choosing, and shoot/throw/hurl at an enemy within 30 feet. Roll 4d6 necrotic damage against a CON saving throw, or half damage on a success. You steal HP equal to half of the damage dealt and add to your HP pool but can not exceed maximum HP, OR as a bonus action you can give the stolen HP to an ally within 30ft range.

For each spell slot used above 3rd level, this spell gains an additional 1d6 per slot above 3rd.