Air Elemental Aóratos Visibilis Familiar

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

At level 3 and above, every time you take damage as your Warlock version, you can choose to roll a D20 add the damage you took, and if it totals greater than 15 you can summon this Air Elemental Familiar. You can use the attacks of your familiar as bonus actions. If you die, fall unconscious, or become exhausted the Elemental will disappear. Because of the nature of The Fiend trapped inside of you, you can only control the Elemental as long as it is in the same dimension as you. 

Roll a D20 for an ability check:

If your level is 8-16 and you roll greater than 15 then you summon the Elder Air Elemental.

If your level is 3-7 or you failed the ability check then you summon this version of the Air Elemental:

Multiattack. The elemental makes two slam attacks.

Slam. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage.

Whirlwind (Recharge 4–6). Each creature in the elemental's space must make a DC 13 Strength saving throw. On a failure, a target takes 15 (3d8 + 2) bludgeoning damage and is flung up 20 feet away from the elemental in a random direction and knocked prone. If a thrown target strikes an object, such as a wall or floor, the target takes 3 (1d6) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 13 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.

===End of the Weakest form of your Air Elemental Familiar===