Air Primordial

Regeneration: The Air Primordial regains 30hp at the start of each of its turns. 

Limited Magic Immunity: Unless allowed, the Air Primordial is immune to spells 6th level or lower. Has advantage on all other saving throws against spells and magical effects. 

Magical attacks: Air Primordial's attacks are magical 

Airform: The Air Primordial can enter a hostile creature's space and stop there. It can move through a space as narrow as 1 inch wide without squeezing. 

Cyclone: As an action, the Air Primordial  can make the effects of the Whirlwind spell. DC22

Multiattack: The Air Primordial can make five slam attacks as an action. 

Slam: Melee weapon attack : +19 to hit, reach 10ft, Hit: 38 (4d12+10) Bludgeoning damage 

Whirlwind (Recharge 4-6): Each creature in the Primordial's space must make a DC 22 Strength saving throw. On a failure, a target takes 21(3d12) bludgeoning damage and is flung up 60 feet away from the Primordial in a random direction and knocked prone. If a Thrown target strikes an object, such as a wall or floor, the target takes 12 (2d10 bludgeoning damage for every 10 feet it was Thrown. If the target is Thrown at another creature, that creature must succeed on a DC 22 Dexterity saving throw or take the same damage and be knocked prone.
If the saving throw is successful, the target takes half the bludgeoning damage and isn't flung away or knocked prone.

The Air Primordial can take 5 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 Primordial regains spent legendary actions at the start of its turn. 

Slam: Melee weapon attack : +19 to hit, reach 10ft, Hit: 38 (4d12+10) Bludgeoning damage 

Airglide: The Air Primordial can move its full movement. 

Tornado: The Primordial can make a tornado 10ft in diameter and 40ft high. Any creature caught in the radius makes a DC18 Dexterity save or be flung into the air and launched 30ft in a random direction.