A creature that you can see within range gets some of is vitality drained and transferred to another creature of your choice.

The target creature must succeed on a Constitution saving throw. (DC equals 10 + spell casting modifier + Spell Slot Level + Proficiency Bonus)

On a failed save the target suffer 2d6 necrotic damage. On a successful save the creature suffers only half as much damage.

The life force equal to the amount of damage taken will then be transferred to another creature you can see within 30 feet of the initial target. 

This spell has no effect on constructs and undead.

At Higher Levels

When cast at higher levels, add an additional 2d6 damage for each spell slot above 2nd.

8th Level Casting

When Cast Using a Level 8 Spell Slot, on a successful save the Target will take 14d6 Necrotic Damage.

If the Target fails it's saving throw, then the target will lose half of it's Max HP Value regardless of current HP. If this amount of damage would reduce the Target to Zero, then the Target Dies.

9th Level Casting

When Cast using a 9th Level Spell slot, there is no save and the Target Creature is reduced to 1 HP. The Target creatures MAX HP Value is used as the value when healing the secondary spell target.