Beckoning Conflagration [RS]

Cast a combustion of dark violet flames to silently but violently burst in a 10ft radius sphere in the spell's range. Every creature in that area must make a Constitution saving throw. A creature that fails the save will take 1d12 fire damage, or half as much on a successful save. The spell's range changes to an area within sight if the caster possesses True Sight. The spell does not deal damage to structures, objects, or constructs. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the spell's damage increases by 1d12 and the area of effect increases by 10ft for each slot level above 1st.

At Certain Levels. When casting this spell using a spell slot of 3th level or higher, the caster may concentrate on the spell for up to a minute. When the caster concentrates on the spell this way, the d12 fire damage is treated as initial damage as surfaces within the area are now magically ignited. The first time a creature enters or starts its turn in the spell's area, it takes 3d6 fire damage. Additional the spell's area is silenced, meaning sound cannot pass through or be heard within the area. The spell's area is illuminated with bright light.