Tyrantus' Flame Sweep

You call out to the Ancient Red Dragon Tyrantus, God of the Mountains, and have him purge all who stand before you. You lay out a 30ft wide, 90ft long line in your mind, as a spectral reminiscence of Tyrantus flies overhead, coating that area in flames. All creatures in that line must make a DEX save, taking 10d8 fire damage on a failed save, and half as much on a successful one. The fire spreads around corners. It ignites flammable objects in the area that aren’t being worn or carried.

At Higher Levels: When you cast this spell using a spell slot of 6th level or higher, the damage increases by 2d8 for each slot level above 5th.