Balor's Terrible Gaze (11th Level)

When this spell is cast a line of black energy 30 feet wide and 10 miles long launches from the caster’s eye. All creatures caught within this line must make both a Dexterity saving throw and a Constitution saving throw. Creatures take 20d12 necrotic damage, 10d10 force damage and are petrified. If a creature succeeds on just the Constitution save, they are not petrified. If a creature succeeds on just the Dexterity saving throw the creature takes half damage but is still petrified. If a creature succeeds on both save, they take one quarter of the damage and are not petrified. A creature petrified in this way can repeat the constitution saving throw at the end of each of its turns. The repeated saving throw is with advantage if the caster is not looking in the direction of the creature. The initial Constitution saving throw is made with advantage if the creature is not looking at the caster at the time of the casting.