Azmodium's Flame Strike

Launch forward a wave of flame in a 40ft line, each creature it comes into contact with makes a Dexterity saving throw or takes 10d6 fire damage on a failed save or have as much on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.