Ancient fire

A 5 foot wide sphere of fire streaks towards an object or you can see in a straight line until it hits a solid object or creature. Make a ranged attack roll against the target. On a hit it takes 8d10 fire damage. The creature makes A dexterity saving throw. On a failure, it has the prone condition.

Once this spell is cast, the caster ages by 1d4 years.

When cast with a higher level spells slot:The Fire damage increases by 1d10 for each spell level above 4.