Iron Knuckle

The Iron Knuckle is one of the largest, stockiest foes in The Legend of Zelda franchise. However, they have only appeared in The Adventure of Link, Ocarina of Time, and Majora's Mask. Rebonack and Nabooru (after being brainwashed) are notable Iron Knuckles across the Zelda series.

Characteristics
The Iron Knuckle is a large heavily armored knight, equipped with a sword or axe capable of dealing immense damage. Though quite similar to Darknuts, Iron Knuckles are less common across the series, and usually play the role of stoic guardians as opposed to the more aggressive behavior of a Darknut. The main difference however is that they do not share a Darknut's traditional weakness to attacks from behind. These foes are dueling elites, incorporating much of the same swordplay technique Link does during battle to great effect. These creatures are also known for their unmatched defensive capabilities and long vitality. In their debut, The Adventure of Link, these knights predominantly appear in the temple dungeons where it is said they were "iron warriors" chosen by the King of Hyrule. They fight with both sword and shield, and appear in three varieties of increasing strength: orange, red, and blue, with the Blue Iron Knuckles being capable of shooting Sword Beams.

The Iron Knuckle appeared later as minibosses in Ocarina of Time and Majora's Mask, in the former appearing as a facet of the plot at the Spirit Temple, and in the latter as guardians that appear predominantly under the Ikana Graveyard, protecting tombs. They were distinguished from Darknuts of previous games by their use of huge axes, capable of taking four hearts from Link at every swing, making them the strongest recurring enemy in the games. Their grand size and armor coverage also meant they took many hits to defeat, but their slow attacks and recovery are their weakness. Like in Zelda II, they also come in varying strengths and colors, with one in particular being larger and having more extravagant armor.

Rebonack
In The Adventure of Link, a Blue Iron Knuckle called  is the boss of the Island Palace. This boss is also known as "The Guardian Ironknuckle" or simply "Ironknuckle", but The Official Nintendo Player's Guide refers to it as Rebonack, an alternate translation of its Japanese name. It rides a levitating steel horse and wields a lance, and charges at Link at a high speed. Seemingly on the back foot against a mounted opponent, Link must use the Down Thrust initially to damage it and the horse. After enough damage is done, it dismounts the horse, and can then be fought as a normal Blue Iron Knuckle. Two more Rebonacks appear as minibosses in the Three-Eye Rock Palace, one of which guards the chamber containing the Cross and the second appearing before the pit that leads to the boss, Barba.

Plot Significance in Ocarina of Time and Majora's Mask
In Ocarina of Time, Nabooru is captured and brainwashed by Koume and Kotake, a pair of Gerudo witch sisters. Koume and Kotake then force the brainwashed Nabooru to protect the entrance to the final chamber in the Spirit Temple as an Iron Knuckle. Her armor is larger and more regal than any other Iron Knuckle. Nabooru is unique in that her armor falls away and harmlessly reveals her upon defeat, apparently releasing her of her hypnosis before being spirited away.

In Majora's Mask, there are only three Iron Knuckles: two are beneath the Ikana Graveyard on the first and second day respectively: one is guarding the resting place of Flat and the other is guarding a Piece of Heart. The third is on the Moon in the hide and seek game played by Link while in his Hylian form. Also in Majora's Mask, gold Iron Knuckle armor can be seen on display in the Curiosity Shop. The significance of this armor is unknown, but it is interesting to note that the armor wields a sword like their appearances in Zelda II, not an axe.

Weaknesses
Iron Knuckles in The Adventure of Link are experts at defensive strategy, using a shield they constantly move up or down to block Link's attacks while also attacking high and low. Link must also focus on defense and watch the swing of its sword and block accordingly while looking for an opening. He should use the Shield magic to protect himself when fighting them. It is also possible for Link to jump and perform a low stab at its head to inflict damage. In Ocarina of Time and Majora's Mask, they are particularly weak to Jump Attacks while they recover from failed axe strikes. The armor of the Iron Knuckle can be damaged, providing two stages to every battle. While wearing armor, they're slow and impervious all attacks save for sword swings and Bombs. Once enough armor is removed, they become enraged and move quicker, but are now weak to arrows, opening up the opportunity for a successful long-range strategy. Despite their similarity to Darknuts, it is not recommended to attack an Iron Knuckle from behind, as they can perform a fast, deadly spinning attack to counter such a strategy. Nayru's Love is particularly useful when fighting Iron Knuckles due to the extensive damage they cause.

Zelda: The Wand of Gamelon
Iron Knuckle appears as the boss of Tykogi Tower in Zelda: The Wand of Gamelon.

Based on the Iron Knuckle of The Adventure of Link, he guards Mayor Kravindish's prison chamber. He shouts that since Zelda walked past him, she defied him and must die. It has been noted his voice and appearance are uncannily similar to Militron of Link: The Faces of Evil. He is struck down using the Power Glove, breaking apart to reveal a Heart Container. Two Armos arrive and quickly decide to leave before Zelda kills them, too.

Strategy
Iron Knuckle's only weakness is the Power Glove, therefore Zelda must get in close enough to use it. A single strike is all that is required to finish him off. However, this also gives him a chance to strike Zelda.

Theory
The fact that other Iron Knuckles dissolve completely when defeated in Ocarina of Time and Majora's Mask would lead to believe that they are animated by magic. However, carefully positioning the game camera through them reveals a Gerudo with a vacant stare similar to Nabooru—in fact, since the body models happen to be virtually identical, it is thought that the head models are incidentally an earlier design of Nabooru. Though this head was removed from Ocarina of Time 3D, their body type is still present as it was in Ocarina of Time and Majora's Mask, meaning it is intentional. This would mean that all Iron Knuckles are actually heavily-armored Gerudo. It is unknown if they were enchanted or if they retained their consciousness; their strange voice and movements may indicate the former, but they fight to the death rather than fight until their spell is broken (which is also reminiscent of Soldiers from A Link to the Past). Their presence in Majora's Mask is also suspect if that were the case.

Trivia

 * In the Japanese version of The Adventure of Link, Iron Knuckle's Sword Beams flash and will disappear when blocked, much like Link's own, but in the NES version, they will not flash and will bounce off of Link's shield. The NES Game Atlas referred to these attacks as knives, rather than beams.
 * In Ocarina of Time, the armor within which Nabooru is encased looks slightly different than that of the other Iron Knuckles fought in the game, particularly the helmet. It also does not wield a weapon until the fight begins, instead it summons an axe from thin air by snapping its fingers.
 * Onox, the main antagonist of Oracle of Seasons, highly resembles the appearance of an Iron Knuckle. The only real difference is that Onox wields a Ball and Chain while Iron Knuckles tend to use axes.
 * Iron Knuckles from Ocarina of Time and Majora's Mask wear a cloth tunic bearing Gerudo patterns, similar to those seen on Ganondorf's and Twinrova's clothing.