Crystal Hail

You summon a jagged crystal sphere that floats 20ft above an area that lasts for 1 minute. As a bonus action, you can command the sphere to rain down a piercing crystal hail on a number of targets within a 30ft cube of it equal to your wizard level. Each target must make a Reflex save. On a failed save, they take 2d6 piercing damage, taking half as much damage on a successful save.

The crystal sphere has a 10 AC and 1 hit point, and spell immunity. If destroyed, the crystal explodes and deals 2d6 damage to all creatures within its 30ft cube, dealing half as much damage on a successful Reflex save.

The number of damage dice increases by 1d6 for each spell slot cast above 2nd.