Beam of bright Annihilation

A beam of blinding light lead by a rock rockets forward at incredible speed,  extending from your hand in a straight beam 5ft wide, 360 ft long or less. Anything within this beam must make a Dexterity saving throw, on a failed save it takes 15d6 lightning damage and 15d6 piercing damage, on a successful save it takes half damage. Also, any creature within 60ft of the beam must make a Dexterity saving throw (the DC save for this throw is your spellcasting modifier), on a failed save they take 7d6 thunder damage and their deafened for 5 minutes, On a successful save they take half damage and is deafened for 1 minute.