Air Knife

Air Knife, also known as Air Lance or Air Lancet, is a recurring weapon in the series. It is usually a mid to high-level knife that inflicts Wind elemental damage when attacking, and is usually one of the few Wind elemental weapons in the games it appears in.

Final Fantasy III
Air Knife is a high-level Knife that can only be used by Onion Knights, Thieves, and Ninjas. It provides +89 attack, +6 Agility, and inflicts Wind elemental damage when attacking with it. It is found in the Sunken Cave.

Final Fantasy V
Air Knife, originally called Air Lance, is a high-level knife that inflicts Wind elemental damage when attacking with it. It provides +53 attack, and can be either bought in Moore, or stolen from Moss Fungus. It can be used by almost any class.

Final Fantasy VI
Air Knife is a mid-level knife, and can only be used by Locke, Strago, and Relm. It has an attack of 76 and is Wind elemental, and can only be obtained in the World of Balance only.

Final Fantasy Tactics
Air Knife is the second strongest knife in the game, with Zwill Straightblade being the strongest. It has an attack of 10 and Defense of 5%, is Wind elemental, and can be bought in Chapter 3 for 8000 Gil or poached from Ahrimans.