Ekzykes' Decay

You roar, lifting into the air and channeling the head of Ekzykes, the Decaying to spew breath of the scarlet rot. You gain a flight speed of 15 feet for the duration. Until the spell ends, you can use your action to breathe scarlet rot in a 30-foot cone. Each creature in the area must make a Constitution saving throw. On a failed save, a target takes 2d6 necrotic damage and is afflicted with scarlet rot for the duration.
An afflicted target makes another Constitution saving throw at the end of each of its turns. On a success, it is cured of the scarlet rot afflicted by this spell.
At Higher Levels.
When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d6 for each slot level above 4th.