ashes to ashes

You ignite yourself with an immense, fire explosion that deals devastating damage to all creatures around you, including yourself. This spell effect occurs at the start of your next turn. it ignores resistances to fire damage and treats immunity to fire damage as resistance

except creatures within 10 feet of you, all creatures with 150 feet of you must succeed a constitution saving throw taking 10 D 10+ additional fire damage on a failed save, or half as much on a success creatures take more damage the closer they are to you

if within 90 feet an additional 25, within 45 they take 50 fire damage and if within 20 feet they take 75 fire damage

creatures within 10 feet of you do not roll the saving throw and take an additional 100 damage