Caustic Blood

Your blood becomes caustic when exposed to the air. When you take piercing or slashing damage, you can use your reaction to select up to 3 creatures within 30 feet of you. Each target takes 1d10 acid damage unless it makes a successful Dexterity saving throw.

Using a Higher-Level Spell Slot. When you cast this spell using a spell slot of 3rd level or higher, the number of targets increases by one for each slot level above 2nd, to a maximum of six targets.