Cloud Giant King

Keen Smell. The giant has advantage on Wisdom (Perception) checks that rely on smell.

Storm Fury (Thunder) aura 20ft; any creature that enters or begins its turn in the aura takes 10 thunder damage;

Innate Spellcasting. The giant's innate spellcasting ability is Charisma. It can innately cast the following spells, requiring no material components:

At will: detect magic, fog cloud, light, shocking grasp

3/day each: feather fall, fly, misty step, telekinesis

1/day each: control weather, gaseous form

Multiattack. The giant makes two morningstar attacks.

Morningstar. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 32 (2d8 + 9) piercing damage and  (3d8) lightning damage.

Hurl Thunderbolt. Ranged attack 100ft; DC15 Dex save. ;  lightning and thunder damage, and the target is pushed 15ft. Hit: 31 (4d10 + 9) lightning  damage.

Howling fury. When reduced below 100 hit points, the Cloud Giant King immediately casts his howling fury ability and makes one morning star attack.

All creatures within 20ft must pass a DC 17 Constitution saving throw or be moved back 20ft take Hit: 21 (6d6) lightning  damage.

and are knocked prone. Creatures making the save take half damage and suffer no other effects.