Cinder Storm Rite

Creatures of your choice within 10 feet of you take 15 irreducible Fire Damage and you and one creature of your choice have immunity to Fire Damage.
Whenever you deal Fire/Radiant Damage with a
weapon attack, you can attempt to hit everything
in a 40 ft long and 5 ft wide line of fire and magma.
All creatures in the line must make a DEX Save
or take 8d10 Fire/Radiant damage, are BLINDED
& all non-magical flammable objects are set on fire.
On a success, they take half that damage.