Onion equipment

The Onion Equipment is a set of gear exclusive to the Onion Knight job. It is the strongest equipment in the games where it appears, and the set is usually made of Sword, Shield, Helmet, Armor, and Gauntlets. The pieces of this gear may carry status boosts and buffs, as well as debuff protection, though the basic defense, attack power, and magic defense granted is enough to endure even the hardest battles without problems. The only downside of this equipment is that in most appearances, the difficulty of obtaining it is very high.

Final Fantasy III
Onion Sword, Helm, Gauntlets, and Armor make the gear in the first game it appears. All the pieces are a very rare drop of Dragons from the Crystal Tower. All of the dragons may drop all parts of the gear in the NES version, but in the Nintendo DS version, Yellow Dragon drops Onion Helms, Red Dragon drops Onion Armors and Green Dragon drops Onion Gauntlets, while Onion Swords and Shields can be dropped by all of them. The Onion Blade also exists and is the Legendary Smith treasure for the Onion Knight

There is also a glitch in the NES version that allows the players to obtain the full set right at the Altar Cave, and allows the player to execute the Fully Equipped Onion Knight Strategy (FEOKS) as early as the player reaches Ur.

Final Fantasy IV
The Onion Sword is available only in the Nintendo DS version by trading it for the Red Tail, and in the same manner the Onion Shield can be acquired by trading the Blue Tail, the Yellow Tail can be traded for the Onion Gloves, the Green Tail can be traded for the Onion Helm, and the Black Tail for the Onion Armor, to the Tail Collector in Adamant Isle Grotto.

Final Fantasy XI
New characters who start as a Warrior will begin with an Onion Sword. It is one of the weakest swords, and should be replaced once the player accumulates some gil.

Final Fantasy XII
Onion Arrows, Bolts, Shot, and Bombs appear as the weakest ammo of each type in this game.

Final Fantasy Tactics
Onion Equipment can only be obtained by using the Multiplayer mode of Final Fantasy Tactics: The War of the Lions. It is by far the strongest equipment in the game, and it makes the wielder virtually undefeatable, but it is also the hardest to obtain.

Final Fantasy Tactics Advance
The Onion Sword appears in this game as a Sword, and it can be equipped by Soldiers, Warriors, and Dragoons. Unlike the other appearances, it is not very strong, and it doesn't teach any ability, but it grants some bonuses to defense, magic defense, and evasion.

Final Fantasy Tactics A2: Grimoire of the Rift
The Onion Sword appears in this sequel as well, again as a Sword, and it can still be equipped by Soldiers, Warriors, and Dragoons. The new Spellblade job can also equip it, and learns the ability "Confusion Blade" from it. Unlike the latter game, it is now a moderately strong weapon, and grants the same defensive bonuses as before.

Etymology
The adjective of Onion refers to the Japanese belief of poverty, aptly named the "Onion Life", "peeling away one layer at a time and crying all the way".