Replace Clive's current weapon with Odin's blade. Landing abilities with the Arm of Darkness fills the Zantetsuken gauge. Hold
to execute Zantetsuken.
Description
Arm of Darkness is Clive's Eikonic Feat ability in Final Fantasy XVI, used (default controller scheme) with 
when Clive has Odin equipped in battle. It replaces Clive's equipped sword with Odin's blade, changing his moveset: parry becomes steel counter, lunge and combo are different, and precision dodge becomes flash of steel.
While each individual regular strike is weaker than with Clive's normal weapon, each damage-dealing move with the Arm of Darkness builds up Zantetsuken instead of Limit Break. Zantetsuken, Odin's signature move from the Final Fantasy series, replaces burning blade, and is used by holding 
. A Level 5 Zantetsuken is one of the most damaging moves in Clive's arsenal.
Performing Level 2 or higher Zantetsuken five times (excluding battles in Hall of Virtue) earns the trophy Every Damn Sinew. Performing three steel counters (excluding battles in Hall of Virtue) earns the trophy Fistful of Steel.
Odin also uses a variant of Zantetsuken during his battle with Ifrit, growing his blade to gigantic proportions. The attack is only named in the Japanese dub. As an enemy ability, Zantetsuken is used by Barnabas Tharmr.
Obtained[]
Clive gains access to Odin's powers as part of the story, during "The Last King", usable in his loadout after the events at the top of Reverie.
Mechanics[]
Clive can use Arm of Darkness in battle whenever he is equipping his dark loadout, though the player can assign other elemental Eikons' mastered Eikonic Abilities as the rechargeable skills. Eikonic Feats have no cooldown.
Using Arm of Darkness with replaces Clive's equipped weapon with Odin's darkness-infused blade. This cannot be done during another ability's animation. Pressing the button again returns Clive's normal weapon and stance. Each attack with Odin's sword is weaker than with Clive's own weapon, and does not build Limit Break, but Clive gains a different moveset and each hit with the sword charges Zantetsuken, unleashed with holding the attack button. Striking Lightning Rod with Odin's blade expedites the charging rate.
The melee attack combo is different with Odin's blade, and does not chain into a magic burst. Lunge (magic + melee buttons together) also changes to a different move than usual.
Zantetsuken Lv. 5.
The initial maximum level for Zantetsuken is three, but upgrading the ability raises it to five. Each tier has a different animation.
Precision-dodging an enemy's attack with Arm of Darkness out allows Clive to counter-attack with Flash of Steel. Parrying with Odin's blade performs Steel Counter (the parry animation was changed in version 1.31).
Holding and releasing with Odin's sword performs Zantetsuken. When the Attack command changes into "Zantetsuken" in the bottom right of the screen, the ability is ready (there is also a sound effect and a color change to the weapon). The player is required to hold the attack button slightly longer in comparison to when using burning blade.
If the player has not charged the ability up, they will perform Level 1 Zantetsuken. The base skill is still good, but each subsequent tier is better. Any built up charge will be saved if the player dispels the weapon or switches loadouts. The player can hold the attack button during an Eikonic Ability animation, and while still holding the button engage Arm of Darkness with as soon as possible and then release the attack button to immediately follow up with Zantetsuken. Powering up Zantetsuken during an Eikonic Ability's animation ensures that Clive will not be interrupted, as any disruption will cancel it out.
Arm of Darkness is mastered in the abilities menu by expending 5000 AP to raise the maximum Zantetsuken level to five.
| Technique | Effect |
|---|---|
| Lv. 1 Zantetsuken | Perform Level 1 Zantetsuken. Using the Level 1 version of the skill does not decrease the charge gauge and still does good damage. |
| Lv. 2 Zantetsuken | Perform Level 2 Zantetsuken. |
| Lv. 3 Zantetsuken | Perform Level 3 Zantetsuken. |
| Lv. 4 Zantetsuken | Perform Level 4 Zantetsuken. |
| Lv. 5 Zantetsuken | Perform Level 5 Zantetsuken. Freezes time so only Clive can act for its duration. Final slash does not do damage but destroys all enemies that lack a will gauge. |
| Flash of Steel | Precision-dodge and counter-attack when wielding Odin's blade. |
| Steel Counter | Parry and press the attack button again. |
Use[]
Arm of Darkness is a great ability to have at Clive's disposal, focused around charging up Zantetsuken and then unleashing it to devastating damage. If the player is using the dark loadout, Arm of Darkness is worth mastering to raise the maximum Zantetsuken level to five. All of Odin's abilities, bar Rift Slip, are focused around charging up Zantetsuken, as they do little damage as standalone Eikonic Abilities.
An easy way to charge Zantetsuken is with Odin's most expensive Eikonic Ability, Dancing Steel, with the accessory that improves Zantetsuken's charge by 25% (50% in New Game Plus); with this setup, Clive can max out a Level 5 Zantetsuken in one cast; the more enemies Dancing Steel targets, the faster Zantetsuken will also recharge. The player can hold during Dancing Steel's animation to immediately follow up with Zantetsuken.
Against normal enemies, a Level 5 Zantetsuken should defeat them all; this is great in areas in Ash after finishing Reverie, where waves of Akashic will come after the player. Against bosses and formidable foes, Zantetsuken is great when they are staggered, as its freezing effect will also stop the enemy's stagger gauge from recovering for its duration.
The highest level Zantetsuken has infinite range in that it will hit all foes that are currently engaged in the battle with Clive.
Level 3 Zantetsuken, however, is often plenty powerful enough to defeat normal enemies even from full health, and so Arm of Darkness is still good even before mastering, and even with Level 5 unlocked, Level 3 can often be available more frequently. The downside is that it may not always hit every enemy, unlike Level 5.
Clive can charge up Zantetsuken twice as fast by striking an enemy and Ramuh's Lightning Rod simultaneously. The player can also simply place the rod on the battlefield and then lunge into it with Odin's blade and/or use Gungnir or even Dancing Steel on it. Lightning Rod can be repositioned to make it easier to hit both the enemy and the rod with Odin's skills.
Arm of Darkness's downside is that always doing Zantetsuken as fast as possible can get boring.
In Odin's chronolith trial, Hand of Enceladus, landing a Level 5 Zantetsuken earns a 15-second time bonus and performing a Steel Counter earns a 5-second time bonus.
Other versions of Zantetsuken[]
You are not my equal, and your will is forfeit!
Barnabas Tharmr using Ultimate Zantetsuken
Odin's Zantetsuken against the Enterprise and the Phoenix.
Odin also uses "Zantetsuken" as a cinematic attack during his boss encounter at the Naldia Narrow. Barnabas, meanwhile, uses "Ultimate Zantetsuken" if not enough damage is dealt to him when the final phase begins, dealing heavy damage that may be fatal.
Ifrit's "Zantetsuken"/"Zantetsuken Reverse".
Clive uses a version of "Zantetsuken" as Ifrit after breaking Odin's sword during the Eikonic clash over Naldia Narrow. While this use is named Zantetsuken in the English version of the game, it has a name similar to Zantetsuken Reverse (大斬鉄返し, Dai Zantetsu Gaeshi?, lit. Great Iron Cutter Reverse) in Japanese (the attack used by Seifer in Final Fantasy VIII to defeat that game's Odin).
Etymology and allusion[]
Zantetsuken (斬鉄剣?) is Japanese for "iron-cutting/slashing iron sword". It normally refers to a blade formed out of exotic materials rumored to be able to cut through steel and/or iron. The term was often associated with blades created by the feudal swordsmith known as Kobayashi Yasuhiro.
In the Final Fantasy series, Zantetsuken is a recurring Instant Death move used by Odin, which the player can commonly utilize by gaining him as a summoned monster. This use of Zantetsuken is alluded to in Final Fantasy XVI when Barnabas uses it to defeat Clive in one blow, and when Odin uses it to seemingly erase matter from existence. Clive's Zantetsuken Level 5 culminates in a cut that deals no damage but the animation slices regular enemies in half and defeats them instantly.