Caustic Blood 2014

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 three creatures within 30 feet of you. Each target takes 1d10 acid damage unless it makes a successful Dexterity saving throw.

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.