Drain Life

You can weaken one foe by lowering its maximum hit points.  Choose one creature that you can see within range to make a Constitution saving throw.  If it fails, 2d8 + your spell casting modifier worth of hitpoints are subtracted from its maximum until it completes a long rest.  If this effect reduces the target's total hit points to zero, it dies.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you can target one additional creature for each slot level above 2nd.