Eruption

Focusing on your pile of rocks laden with ash, a volcano will grow, ready to erupt. 

As the volcano grows to 100ft tall with a 25ft radius base, it will push all creature away from it. Creatures who have not seen a volcano before have to make a WIS save of 13 or be frightened of the volcano growing. The volcano will stay there for 12 hours. Once grown, the volcano starts to spew lava. Lava will spread at a speed of 30ft. Lava will also be flung anywhere within 50ft of the top of the volcano. 3 balls will be flung every 1 minute for 10 minutes before stopping then repeating every 2 hours until it disappears.

The lava being flung can be used to target players. Targets must succeed a DEX save of 19. A failed save takes 3d12 fire damage and half on a successful one. The lava will burn any flammable object as it descends and spreads. When the lava touches a person, the person takes 3d8 fire damage per minute as they are in the lava. Lava stops flowing after 5 minutes. Once the lava has reached the bottom, 4 magma mephits will appear from the side of the volcano. Once the lava stops and cools, 6 more magma mephits appear from the lava on the ground. 

The lava, volcano and mephits will all disappear after the spell has faded after 6 hours