The Nameless King's Holy Lightning Storm

Miracle of the Nameless King, ally to the ancient dragons in the old times.

Calls forth a hailstorm of furious golden lightning bolts. choose a point that you can see. All targets within a 15-foot area centered on that point must make a dexterity saving throw and a constitution saving throw. upon a failed dexterity saving throw, the target is knocked prone and blinded. A successful save simply results in the target becoming prone. A failed Constitution save results in 3d10 lightning damage and 3d10 radiant damage. A successful save halves this damage, rounded up.