Conjure Super Duper Volleyball

You summon a flaming volleyball that appears in an unoccupied space you can see. As an action, you or another creature you choose can Spike the volleyball at one target in sight. They must make a ranged spell attack using your modifier. On a hit, the target takes 8d12 + 10 magical bludgeoning damage, and 2d12 + 10 fire damage. Additionally, they must make a Constitution saving throw. On a failed save, they are Stunned for 1d4 rounds.