the explode in a burst of primordial elements. all creatures in a 25 foot sphere centered on you must make a dexterity saving throw, having one of the the effects below happen to a creature on a failed save, you choose which one for each creature.

Earth. the creature takes 2d8 bludgeoning damage, and is restrained for a round. 

Air. the creature is pushed 30 feet away from you. is a creature being pushed away from you hit's an object, it takes 1d6 bludgeoning damage for every 10 feet it  was pushed before hitting the object. if the creature hit's a creature, that creature is knocked prone, and both creatures take 1d4 bludgeoning damage for every 10 feet the creature was pushed before hitting the creature.

Fire. the creature takes 5d6 fire damage.

Water. the creature takes 1d10 cold and bludgeoning damage, and is knocked prone. then, you can choose to move the creature 5 feet in any direction. instead, you can choose to heal a creature effected by this element by 1d10 + your spellcasting ability modifier.