Volcano

Using the power of magma and lava at your disposal, you create a mass of volcanic rock, in which you can see at any distance. When created, you create land out of air to do so, meaning you effectively create a new land mass. Any creature within 5 miles of the new volcano must make a Con save against your spell save DC, or suffer a level of exhaustion, and 5 D12 + your number of hit die fire damage. Immediately after casting the spell, roll a D4-1, and the number you roll, if is not a 0, determines the amount of times the volcano erupts. Upon an eruption, anyone or anything must make a Dex save of 18 or higher, or be affected by the eruption, being knocked prone. Anyone hit by flying debris takes 1D10 bludgeoning damage. The eruption spews noxious gas into the air, making it hard to see and breathe. Anyone affected by the gas must make a Con. save of 18 or higher. On a failed save, one takes a level of exhaustion, knocked unconscious, and is incapacitated for the next minute, or until their awoken. Anyone hit by debris from the explosion must make Dex. saving throw. On a fail, they are hit by a exploding rock, causing 20D8 fire damage, and 10D6 bludgeoning damage.

At level 9, you gain control of when the eruptions happen, and the general direction of which the explosions happen per cast spell. If you cast this spell 5 times in % consecutive years, the volcano becomes permanent, but in-active. The only way for it to erupt again is to use an Eruption spell on it,  in which apply the eruption effects on it.