Your patron is a noble djinn or Yan C Bin, evil Prince of Elemental Air.

Passionate, mischievous and subtle describe all elemental air patrons. When displeased they do not show their displeasure overtly, so any warlock walking this path must tread lightly lest they raise their patron's ire. While the kindest and most beneficent of the Elemental Patrons, they are not truly kind nor beneficent. If you are looking for a patron with these traits look elsewhere, for this type of patron never has them. Some are malicious, many may trick you into a pact, but their true goals are always to fulfill their insatiable sybaritic appetites.

Special Pact Conditions

These patrons are at odds with the powers of the Elemental Plane of Earth. You are charged with destroying any denizen of that plane you come across. (Killing earth genasi is not required, but may gain you some favor with your patron.)  You are further charged with the freeing of any denizen of the Elemental Plane of air that is imprisoned by mortal magic and the slaughter of those who dare to create or use such prisons as a Djinni Bottle or an Iron Flask. While not charged to do so overtly, your patron expects extravagant gifts from you for deigning to deal with such a lowly mortal.

Binding Mark

Color leaches from you and everything you wear. At first level you seem a little pale, by 20th level you are completely colorless and parts of you may seem translucent.

 Pact Boon

Pact of the Chain: your familiar is a ice mephit or a steam mephit.

Pact of the Blade: your pact weapon is invisible.

Pact of the Tome: your book of shadows manifests as a smoking bottle; a continuous stream of smoke issues from it and dissipates a foot from its lip when unstoppered. When you gaze into the smoke, you can see your spells written in it's convolution.

Pact of the Talisman:  a 4" globe of force containing a pure mote of Elemental Air from the Elemental Plane of Air. Whomever bears the Talisman has resistance to lightning and thunder damage and advantage on saves vs lightning and thunder damage.

Expanded Spell List

You learn Gust as a warlock cantrip which does not count against your warlocks cantrips known. Your Air Patron also lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Air Patron Expanded Spells

SPELL LEVEL	SPELLS
1st	fog cloud, thunderwave
2nd	dust devil, gust of wind
3rd	lightning bolt,wind wall
4th	storm sphere, greater invisibility
5th	cloudkill, control winds

Weight of the Wind

You are granted The Charm of Feather Falling while your patron is not displeased with you. At 6th level, as a bonus action, you can cast gaseous form on yourself once between rests without expending a spell slot. This spell need not be in your Warlock spell list to do so.

Call Elemental

Starting at 6th level, you can call for an air elemental with HD equal to half your level (round up) to come to your aid once between rests. 

The elemental makes a wisdom saving throw vs your spell save dc. If successful, no elemental answers the call.  Otherwise, the elemental appears in the nearest open space close to you, is friendly to you and acts immediately after you in the round. The elemental remains a maximum number of rounds equal to your Warlock spell save dc, or until you thank and dismiss the creature as a free action. 

Frequent usage of this feature, or if called elementals are abused by you or your allies will cause future callings to be less likely to succeed. (Saves vs this feature will be made at advantage.)

Greater Storm Resistance

At 10th level you gain Greater Storm Resistance; you have resistance to thunder and lightning damage and save vs thunder or lightning at advantage. If you otherwise have thunder and/or lightning resistance, you gain thunder and/or immunity instead.

Elemental Form

Starting at 14th level, as an action, You can expend a pact slot to transform into an air elemental. All equipment carried, worn or wielded transforms with you.

You can maintain the transformation without concentration a number of minutes equal to your level on the prime material plane, indefinitely on an elemental plane or a number of rounds equal to your level on any other plane or demi-plane.

You may end the transformation as a free action and it ends automatically if you are killed.

Once you use this feature, you can’t use it again until you finish a long rest.