Before the Flood

You focus your hands, spiraling in a motion as you mutter the words to bring forth the primordial chaos into the fray once again. You point your finger toward an area, and a 120 ft cube begins to shape the land. The entire area becomes difficult terrain, and the area changes. Pick one of the elements, and the following effects take place in your affected area:

• Fire: The land cracks and breaks, as geysers of fire and lava spew around as the very air itself ignites. All targets that start their turn in the area or enter it for the first time must succeed on a Dexterity saving throw against your spell save DC. On a failure, the target takes 7d12 fire damage or half as much on a success. If a target remains in the area and fails again, they take an additional 3d12 fire damage. Even if a target leaves the area, they will continue to take 3d12 fire damage at the start of their turns until they succeed on a dexterity saving throw. Targets that succeed on the saving throw at the start of their turns outside the area take no burn damage.
• Earth: The ground is torn asunder as mountains protrude and crevices form constantly, the rock moving through the entire area like a sentient being. All targets that start their turn in the area or enter it for the first time must succeed on a Constitution saving throw against your spell save DC. On a failure, targets take 6d10 bludgeoning damage and are  restrained. On a success, targets take half as much damage and are not restrained.
• Air: The ground swirls and forms into a cyclone, moving freely within the area. The Cyclone has a smaller area, a cylinder 20 ft. wide. You can move the Cyclone 40 ft. at the start of your turn, so long as it remains within the square. All targets outside of the cylinder that start their turn or enter in the area for the first time must succeed on a Dexterity saving throw against your spell DC, or take 2d8 slashing damage as the wind lashes against them. Targets within the Cyclone must succeed on a Strength saving throw or get launched into the air, flying to the top of the square's height and fall in a random direction (d8 determined for direction) 30 ft away from the cylinder, taking 6d6 bludgeoning damage as they fall to the ground and are knocked prone.
• Water: Torrents of water flood the area, and the ground beneath the spell becomes a bottomless sea. Heavy rainfall fills the area, causing any flying targets by any means to make a Strength saving throw against your spell save DC or drop from the sky. Creatures that do not have an innate swim speed move at 1/4 of their total speed while in the water. Creatures that start their turn in the water or enter it for the first time must succeed on a Constitution saving throw against your spell save DC, or fall beneath the waves. Creatures that end their turn underneath the water take a point of exhaustion.

The effects last for one minute, and as a main action on your turn you can change to a different element. There is a fusion effect when changing elements, combining the strengths of whichever realms you swap to. This can combine in interesting ways during the transition, such as Water and Air causing Lightning to strike down, or Earth and Fire to create fields of lava. There are many combinations of such, and for the sake of simplicity will be left up to the DM. The damage of this transitioning turn should not exceed 8d10 of any damage type, and it should not provide additional utility.