Banefire

"Primal flames, leave no trace of this beast behind! Banefire!"

As you hold the crystal that serves as this spell's material component, dragonfire erupts from it away from you, forming a line 100 feet long and 5 feet wide. Each creature in the line must make a Dexterity saving throw. A creature takes 35 (10d6) fire damage on a failed save, or half as much damage on a successful one. This spell's damage overcomes resistance.

This spell ignites flammable objects in the area that aren't being worn or carried.

This spell is difficult to interrupt with counterspell and similar effects; the caster of such an effect must succeed on a spellcasting ability check to cause this spell to fail, regardless of the spell level used to do so. If this spell's level is high enough that a spellcasting ability check would normally be required to interrupt the spell, that check is made with disadvantage.

At Higher Levels: When you cast this spell using a spell slot of 7th or higher, the damage increases by 1d6 for every spell slot above 6th. If this spell is cast with a 9th-level spell slot, this spell overcomes immunity to magical damage, magical effects that would cancel the effect of this spell fail, and antimagic field cannot suppress this spell's effect unless that spell is cast using a 9th-level spell slot.