Bigthan's Blood Befoulment

You attempt to turn a creature's very blood into acid. The target must make a Constitution saving throw. The target takes 13d4 Acid damage on a failed save and they have disadvantage on all Constitution saving throws and attack rolls for 1 minute. They take half as much damage on a successful save and do not have disadvantage on Constitution saving throws or attack rolls. This spell has no effect on undead or constructs.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, you can target one additional creature for each slot level above 5th. The creatures must be within 60 feet of each other when you target them.