Air elementals are creatures formed of wind and air itself. They reside on the elemental planes, and are called forth to this world by wizards, clerics, druids, shamans, and other spellcasters. They are bound into service for a time, due to ancient agreements and pacts, and then released, sent back to their homes.
You may want to get rid of the standard air elemental's vulnerability to fire, which doesn't make much thematic sense.
Aerial Servants and Invisible Stalkers
Despite rumors to the contrary, these "creatures" are magical constructs created by the spells that supposedly "summon" them, not true elementals.
Ritual: Bind Air Elemental
This ritual calls up and binds an air elemental to your service for one day. It is a fairly standard elemental binding pact.
|Bind Air Elemental|
|You form the winds themselves into an elemental gate, summoning forth a willing servant for the day.|
Casting Time: Short Rest
Duration: Until the end of your next Extended Rest
|Component Cost: 1 Action Point
Market Price: 100 gp
Key Skill: Arcana, Religion, or Nature (Lesser Air Elemental: DC 19; Air Elemental: DC 26; Greater Air Elemental: DC 34)
|Attempt: You choose what strength of Air Elemental you are summoning (and thus which DC you must meet) when you undertake this ritual.
Success: You call up and bind the appropriate elemental to your service. The elemental serves you in any way you command, until the duration expires, until you release it, or until it is reduced to 0 hp (upon reaching 0 hp, it is banished back to its home plane).
Failure: You spend the cost. You call up the elemental, but it rejects the pact, and runs wild, likely engaging you in combat. You cannot try again until after your next extended rest.