Cloud Giant Lord

Control Weather (8th-level Spell). The giant can cast the control weather spell, requiring no material components and using Charisma as the spellcasting ability.

Masks of Emoting.  The giant can wear one of four masks it has in its possession.  Wear these masks gives the giant special effects, including immunity to the charmed and frighten conditions and advantage on Charisma (Deception) checks.  The masks have an AC of 20, 15 hit points, immune to psychic and poison damage, and vulnerable to bludgeoning damage.  A broken mask can be summoned at the next dawn with no damage.  The giant has these masks on their person: 
   Mask of Jubilation: The giant grants all allies within a 30 ft. radius of it advantage on their attack rolls and saving throws
   Mask of Rage:  The giant summons harsh winds within a 15 ft. radius of itself, granting it a +3 bonus to its AC versus ranged attacks.  In addition, creatures attempting to move closer to the giant must make a DC 17 Strength saving throw while within range of the winds or be unable to move closer.  If the creature fails by 5 or more, they are pushed out of the winds and knocked prone.
   Mask of Disgust:  When the giant hits a creature with telekinetic strike, the creature is also pushed back 10 ft.
   Mask of Sorrow:  As a bonus action, the giant can teleport, along with any equipment it is wearing or carrying, up to 60 feet to an unoccupied space it can see.

Multiattack: The giant can switch to another Mask of Emoting and then makes two Telekinetic Strike attacks.

Telekinetic Strike. Ranged Spell Attack: +7 to hit, range 240 ft., one target. Hit: 25 (4d10 + 3) force damage.

Spellcasting. The giant casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 17):
At will: detect magic, fog cloud, light, minor illusion
3/day each: invisibility, silent image,  suggestion, tongues
1/day each: gaseous form, greater invisibility, major image, prismatic spray

The giant can take 3 legendary actions, choosing from the options below.  Only one legendary action option can be used at a time and only at the end of another creature's turn.  The giant regains any spent legendary actions at the start of its turn.

Another Facade.  The giant swaps its mask.