You place too much trust in your Magicks!
Reduces the enemy's Magic.
The formula for Magic Break is as follows:
X Magic Break is found on Auron's section of the Sphere Grid and halves the target's Magic Power. It can be healed by Dispel, and ends if the target is KO'd during battle. It can also be inflicted via the Full Break ability, also found on Auron's Sphere Grid path and via some of Rikku's mixes. Some enemy attacks also inflict it upon the party. Some enemies are immune against Magic Break.
X-2 Magic Break is used by the Warrior dressphere for 4 MP. It takes 30 AP to learn. It deals physical damage to a target and decreases their MAG by -2 levels. It also appears in the form of Magic Eraser, usable by Rikku while in Mascot, which targets all enemies.
XII Addle is a Technick which halves one foe's Magick Power. It has 66% base accuracy and can be used repeatedly, but is not as effective on repeated uses. Once the effect has been applied, it is permanent, and the opponent can't remove it. Addle can be bought in Rabanastre and Archades for 3,500 gil, and can be used for 30 License Points.
FFT Magic Break, known as Rend MP in the PSP remake, is an ability available to the Knight job class, learned for 250 JP, which reduces the target's MP. It reduces the target's MP by approximately half (rounded up).
TA Magicbreak is used by both Soldiers and Warriors. The Fencer's Manastrike is similar to it. Magicbreak can be learned from the Ancient Sword for 200 AP. Magicbreak deals MP damage, the element is the same as the equipped weapon.
TA2 Rend MP is an ability for the Warrior and Soldier classes, learned for 250 AP from the Falchion for the Warrior and by the for 250 AP from the Ancient Sword for the Soldier. It damages a target's MP. The Raptor also has the ability Soul Crush, which in addition to depleting the targets MP, deals damage. It is learned from the Falchion and requires 250 AP to master.