Your pain shall be two-fold.
Reduces the enemy's Defense.
Armor Break is a Sword Arts ability, used by Steiner. It costs 4 MP to use, and can be learned for 30 AP from the Mythril Sword. It has a 50% accuracy rate, but can be used repeatedly. It halves the target's defense.
Armor Break is found on Auron's section of the Sphere Grid. It attacks and sets the target's Defense at 0, as well as nullifying "Armored", meaning that even non-Piercing weapons deal normal damage. The inherent armor property of armored enemies cuts physical damage to 1/3 if attack is not Piercing.
Auron's Banishing Blade Overdrive alongside Frag Grenade (whether by Using or Mixing) are the two only attacks that have 100% chance of inflict Armor Break, in contrast to Armor Break skill that not always inflicts this effect.
Armor Break is available via the Warrior dressphere, reducing the target's defense, but not completely eradicating it. It costs 4 MP to use and 30 AP to learn. While damaging the target, it also reduces the target's defense by 2 which be stacked up to 10. It can also be used via Lady Luck's Attack Reels by rolling a Cherry. It also appears in the form of Armor Eraser, usable by Mascot Rikku, which targets all enemies and reduces their Defense by 3. However, Armor Eraser does not inflict damage.
A technique that destroys the item equipped on the target's body.
Rend Armor is an ability learned by the Knight class for 400 JP. It has an instant cast time, an effect of 0, and its range depends on the equipped weapon's range. It attempts to destroy the target's equipped armor, and in the PSP version, will deal regular physical damage to monsters as well.
Rend Armor is an ability learned by the Master Monk for 350 AP from the Cypress Pole. It attempts to destroy the target's equipped armor and has a range of 1. In addition, it is also used by the Reaver, which in addition to trying to destroy the target's armor, will also inflict non-elemental physical damage.
The Scholar's Subdue ability halves all enemies' defense for three turns at the cost of two AP. Subdue is the second ability learned on the job. The Scholar's ultimate ability, Tame, reduces the enemies' defense to 1, but it only works for one turn.
Shell Split is the job level 3 ability for the Pirate. It deals the same damage as a conventional attack to one target, and for four turns, lowers the target's physical defense by 25%. The lower limit for P.Def is 75%. It costs 9 MP to use.
Shell Split is the level 3 command ability for the Pirate. It allows the user to deal the same damage as a conventional attack to one target, and for four turns, lower the target's P.Def by 25%. The lower limit for P.Def is 75%. It cost 9 MP to use.
Armor Break (Lv1) is a reactive ability that costs 2 CP to equip. It is activated after second enemy appears in Battle Music Sequences (BMS). It reduces the enemy's physical defense and has low strength. it is learned by Warrior of Light (level 20), Cecil (level 25), Edge (level 10), Edgar (initially), Cloud (level 5), Tifa (level 20), Squall (level 15), Auron (initially), Balthier (level 25), Lightning (level 20), Snow (level 10), Benjamin (level 20), Agrias (level 15), and Noel (initially).
Armor Break (Lv2) is a reactive ability that costs 7 CP to equip. It is activated after third enemy appears in BMS and reduces the enemy's physical defense and has medium strength. It is learned by Warrior of Light (level 60), Cecil (level 70), Edge (level 55), Edgar (level 30), Tifa (level 60), Sephiroth (level 20), Squall (level 55), Auron (level 35), Lilisette (level 65), Balthier (level 75), Lightning (level 75), Snow (level 65), Benjamin (level 60), Agrias (level 55), Paine (level 25), Machina (level 25), and Noel (level 30).
Armor Break (Lv3) is a reactive ability that costs 12 CP to equip. It is activated just once in BMS when a boss-class enemy appears. Reduces the enemy's physical defense and has full strength. It is learned by Warrior of Light (level 95), Edgar (level 65), Tifa (level 95), Squall (level 85), Auron (level 70), Agrias (level 95), Paine (level 65), Chaos (level 55), and Noel (level 65).
Damage and reduce DEF for one enemy.
Armor Break is a Support-type special ability that costs 7 MP to cast and deals, to a single enemy, physical damage (1.2x) while also reducing its DEF (15%) for the following three turns. It can be learned by Cloud of Darkness (4★, level 14), Duane (4★, level 34), Leo (3★, level 35), Ludmille (4★, level 42), Russell (3★, level 22), Skaha (3★, level 17), Vaan (4★, level 43), Xiao (4★, at level 17), and Raggles*Japanese version-only (3★, level 20).