Elemental orbs

Create a magic orb of random elemental energy that floats around you. Once cast you can use an action to throw all of your magic orbs within a 10ft radius of a point you choose within range of the spell. Each magic orb deals 1d8 damage in a 20ft radius. For every turn you concentrate add 1d4 damage to each orb. Any creature in the blast radius of a magic orb must make a Dex saving throw, on a failed save they take full damage and on a successful save the take half damage.

As a bonus action you can throw one orb.

  If you fail a concentration check at any point all added damage is lost and the orb detonates on your location.