Cactuar King will counter all attacks with 10,000 Needles, meaning only those with the Break HP Limit ability will be able to withstand it. On its turn the King may unleash 99,999 Needles (50% of the time), which cannot be blocked and is always fatal. Alternatively, he may use 10,000 Needles (40% of the time), or simply do nothing. Once he has done nothing twice, he will no longer do so, but instead has a chance of escaping from the battle (10% of the time). Unlike Qactuar and Cactuar, his remaining HP has no influence on the chance of him escaping. Despite the Cactuar King's relatively low HP compared to other Arena creations, its high Evasion makes it difficult to hit with normal attacks, even if the character's Accuracy is at maximum.
If the Cactuar King escapes, the player will get nothing.
Cactuar King is extremely evasive; the Accuracy stat has no impact on the chance of connecting, which is always 25% before Luck is taken into account. Thus, the remaining 75% must be made up with the Luck stat, or use of Aim, Luck or Jinx. It is often simpler to use attacks that cannot miss; while Cactuar King's magic defense is too high for magic to be practical, Overdrives are an effective method of damage.