Dark Lightning Apocalypse

A beam of shadow electrical energy is fired in a sphere around the caster and launches upwards.

The sky darkens and lightning crackles through the sky as four massive lightning bolts converge on the ground hitting one creature you can see. It must make a constitution saving throw, on a failed save it takes 40d6 lightning damage and it is blinded for 1 minute, or half on a successful one and it is not blinded. It can continue to make constitution saving throws against the blindness effect at the end of it's turn. The release of lightning energy at the point of impact creates a shockwave in a 120-foot-radius sphere Each creature in that radius must make a Constitution saving throw. The sphere spreads around corners. All creatures except the original target of the spell take 40d6 thunder damage and are deafened for 1 minute on a failed save, or half as much damage on a successful one and are not deafened.