Breath of Decay

You inhale untainted air and exhale a miasmic rot.  Each creature in a 15-foot cone must make a constitution saving throw. A creature takes 2d6 necrotic damage on a failed save, or half as much damage on a successful one.

Targets who fail the save are poisoned until the end of your next turn.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for each slot level above 1st.