Blood Assimilation

Necromantic energy washes over a creature of your choice that you can see within range, draining blood and vitality from it. The target must make a Constitution saving throw. The target takes 9d10 necrotic damage on a failed save, or half as much damage on a successful one. This spell has no effect on undead or constructs. When the spell takes affect you suffer 1 fifth of the damage but gain 3d6 temporary hit points.

A minion of Strahd Von Zarovich automatically fails the save, Also their maximum hit points is reduced by that damage and you gain 1 hit point added to your maximum hit points.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage increases by 1d10 for each slot level above 6th.