Since we're working so much with magical warfare it's good to know what is doable and what is not, and to be quite honest I have not been very clear about the limits... there should probably have been added a proper magic chapter in there other than Lily refusing to attend one.

Anyway! Below I list some of common spells for the air element that should hopefully give you an idea of the spells and their level for each rank. 

About magic in general:

Spell Rank: Each spell has a spell rank that matches the level of blessing you'd need to have to perform these spells, as the fairy is otherwise too weak to cast it. If a higher ranking fairy casts lower ranking spells they can choose to vastly expand the effect to about the same level as the rank they themselves are.

Spell Construction: A spell construction is much like a blueprint for the spell. It contains amount of mana spent, duration, range, intensity, spacial transformation of the element, origin point and so on. 

Casting time: You can cast a spell as fast as you can set all parameters, thus specialization and training is in part remembering and setting these rapidly.

Instant spells: Every spell that is not a concentration spell has all parameters set at the construction, which includes origin point and casting direction. For instant spells you cannot change anything about the spell once it's cast, even if an ally gets in the way.

Concentration spells: Most defense spells fall into this category. Unlike instant spells you can change the construction during casting, but they require a constant mana supply which is often higher than with instant spells.

The fairy's part of casting magic: The faerie's work in casting magic is simply to apply the construction. Your magic is based on your own skills

Training and Specialization:

The spells below are merely a subset of all possibilities. A set of general spells or a grouping of spells, so to say. 

A magician does not learn all spells, but instead usually stick to a subset which they then specialize in, as a specific grouping of spells usually have a similar spell constructions.

Some spells have a very simple basic application, such as sending a message with the wind. With practice things such as spreading a sound evenly over an area can be achieved, or silencing magic, which is both applications of said spell, although with a variant. These variants rely heavily on difficult and constantly changing spell construction, so skills factor into it, thus making daily training and practice for these spells necessary. 

General Limitations:

- The gods prevent any effect that affects a living being's body in a positive way. They feel used and will do what is in their power to harm the user. If this negative side effect is attempted used for war or hate the gods do nothing just to piss off the caster more.

I made the decision of preventing this not just because of the story, but also to prevent world breaking. Things such as flight magic change everything when it comes to warfare and would completely change how fortresses are built and so on. The changes to the world would be rather drastic, and something I felt like shouldn't be added here. I also feel as though this adds some more interesting dynamics with things such as illusions as they cannot be used on living beings (plants don't count here). You'll have to be a bit more creative.

General Buffs:

Magic can affect each other. If two mages cast the same spells they can increase the effect, though not always doubly. For wind, something that has a range of 25 meters could be increased to 35 by cooperation. In the same way air magic can spread out a fire magic burst further or make stones from earth magic fly further.

Mana:

Low maximum mana types generally refill their mana 2-4 times a day, but cannot cast large spells or variants of their basic spells that require more mana, such as range increase.

High maximum mana types, as usually found with highly mana blessed individuals, fill their mana to the brim after about two days of rest. This does allow them to cast massive magic, but in turn it takes a long time for them to regain that energy. For an example of this remember when Lionel fought during the field of death and labyrinth chapters where he ran dry on the second day after casting multiple large spells.

Most people fall between these two types of course.

Should you be blessed with a lesser fairy you cannot increase the effect of the spell other than duration and range. You cannot increase strength, damage, intensity, size of objects or get the lower level spells to that of higher ranks. This may mean that reaching the bottom of your mana is hard.

Air Magic

Specific God Limitations:

- You cannot use illusions on your own appearance. You cannot make yourself look different nor make yourself invisible. Those who have tried have ended up as cripples or completely mutated instead.

- You cannot fly. When attempted, the gods use it as an opening to make it fail and usually cause death.

Lesser Spells:

-Aerial Defense: Summons wind to block incoming attacks from the air by buffeting the object with a blast of wind.

-Lesser Illusion: A non-living object smaller than you becomes invisible to the eye. You can also make an illusion of a non-living object up to the size of half a cubic meter.

-Gust of Wind: Creates a blast of wind in a cone up to 25 meters long 3 meters wide at the end. This cannot damage the target directly but can knock them prone. If any objects get caught in the wind they can indeed give damage though.

-Sound Manipulation: You manipulate the air to either carry your voice further or silence an area around you. You can carry a voice or made sound up to 500 meters. This also means you can clearly overhear unobstructed conversations 500 meters away if you know what you're looking for. You can silence an area of a 2 meter radius around yourself.

Moderate Spells:

- Mana's cutting edge: The spell covers the blade of a held weapon in mana. For wind magic it often seems to twirl around the blade. As this spell is not air magic, but mana application, it is difficult to cast and keep running as the mana cost is immense due to its non-air nature. While the spell allows the weapon to cut through metal, though with difficulty, the spell fades instantly upon impact with an anti-magic shield.

- Solitary Cocoon of Defense: You create a vicious cocoon of air around you so violent that even melee weapons have a hard time reaching you. You cannot hear anything around you while this spell is active and the spell cannot be used together with an anti-magic shield. Which ends up swallowing the spell as the wind passes by it. 

- Mist of the Vale: Create fog in a 15 meter radius, visibility is reduced to 2 meters. If not used with concentration the spell fades after a minute. A medium blessed would be able to keep a thick fog going for about 15 minutes, longer if they reduce the thickness of the fog. Gusts of wind can be used to disperse the mist for but a few seconds. Mist near anti-magic shields is devoured, be careful of excessive mana usage due to this as the mist always tries to spread out evenly and requires more mana the more you have to construct.

- Step of the False Ground: You alter the appearance of the terrain within a 30 meter radius. You can make a swamp area look and smell like a beautiful garden. The illusions have no substance and cannot be touched. When an anti-magic shield is moved into the area the illusions within 30 centimeters of the shield fade. This can be kept up for about an hour by an average moderate spell caster before they need a break. Smell and sound can be added to illusions at moderate spells of illusion. Only 'static' objects can be made, so your illusions do not move.

- Dispel Illusions: Illusions cast at lower rank are instantly dispelled, and illusions cast at at the same rank are contested. Be careful of excessive mana-drain. You cannot use this to locate illusions, but if you have a good sense of your mana you'll be able to know that there is one nearby as long as it's the same level and the other user doesn't let you dispel it. You cannot dispel illusions cast at a higher rank than your own.

Grand Spells:

-Wind's Roar: Creates a 3 m x 3 m corridor 10 meters long of tearing and ripping wind. Paper and light clothes are destroyed instantly and heavier clothes are damaged. Other than knockdown, the spell is often known to disarm and send people flying several meters back, in many cases causing severe injuries from the falls.

-Army of Wind: The caster creates a number of illusory figures up to around ~70. These figures may be as vague or detailed as the user wishes though the caster must have seen the objects/people they're making. They are fully mobile and will take whatever actions you desire as long as they do not leave the 30 meter radius around the caster. They can be seen, heard and smelled but cannot physically interact with objects or individuals. A grand mage can keep this going permanently, just as other lower rank illusions. If they increase the area of the illusion they can no longer keep up.

-Wrath of the Wind: Creates a hurricane in a 1 mile radius around the caster, with the caster being in the eye of the storm. Everything weighing less than 300 kg is lifted from the ground. Everyone in the storm that gets lifted into the air meet their certain deaths either from flying debris or the fall. The hurricane can be kept running for up to an hour before the mage would have emptied their mana reserves.

Final Notes:

As you can see there's no wind beheading spells! Anyway! As you can see, air magic isn't based directly on offense, nor do they have the same extent of environment shaping magic as earth magic. Still, they have a lot of tricks up their sleeves that many of the others do not, though some of it would be considered rather dishonorable for knights. 

Finally, some grand level spells can be cast a few times a day, while others can only be cast once. Their level is not entire equal to their mana consumption.