Atomic Bomb

You consume nuclear radiation around and bring the the absolute power of nuclear power at hand. In a 1 mile radius on a location you see, a bright light bursts in the area. Anyone who can see it must make a Constitution saving throw, with disadvantage, or be permanently blinded.

In addition, in that 1 mile radius, the attack instantly kills anyone in there that is below CR 30. If anyone survives, they take 20 radiation damage to every ability score, and this is permanent.

Anyone 1 mile away from the 1 mile radius, will take 250 fire damage that ignores immunity and resistance. They then gain the Blazing Condition Anyone that is within 5 miles of the 1 mile radius must make a Strength Saving Throw, or take 100 Thunder damage and be thrown back 100 feet away from the radius. They are then Toppled/Prone.

When you cast this spell, the radiation fully consumes you. You take 15 Radiation damage to every ability score, and this is permanent. It can only be removed with a Wish Spell, or the Greater Restoration spell casted at 9th level over a period of 1 year.

Radiation Damage. Radiation damage doesn't target HP, it instead targets a creatures ability scores. Radiation damage goes away after a creature takes a Long Rest. Greater Restoration or similar high leveled spells also removes it.

Blazing Condition. The Blazing Condition is a Damage Over Time Condition. Each round a creature has this condition, they take an extra 1d10 Fire Damage. In addition, while they have the Blazing Condition, they are unable to recover hit points. They have disadvantage on attack rolls while on fire. At the end of each creature who is on fire's turn, they can roll a Con save to remove the condition. The DC is the spellcasters DC.