The Calcabrina is a boss in Final Fantasy IV. It appears during the battle with the Calcas and the Brinas after a certain amount of time passes and the enemies are not defeated. If this happens, the Calcas and the Brinas will use Combine, and the party will have to battle the Calcabrina.
Calcabrina can be dangerous because it uses Glance to charm a character and can cause large amounts of damage. If the Calcabrina is not defeated within a certain amount of time, it will revert to the Calcas and the Brinas with all their HP.
Regardless of the game version, it is important that Cecil has high HP at the battle's end; otherwise, the battle that follows immediately after this battle will become very difficult, if not impossible.
In the remake version, Calcabrina is harder, as every single attack the player makes will be countered with a powerful physical attack that deals at least 1,000 HP of damage. Even with adamant armor, the player can still take high damage. Its normal physical attacks do not occur often, but still cause the same amount of damage and can also result in the Charm status. Only Black Magic attacks (cast with items such as a Bomb Fragment) can be used without fear of being countered, but as none of the group has enough Black Magic power to seriously damage Calcabrina, this is not a reasonable strategy. Calcabrina is susceptible to Rosa's Hold spell, which will render it unable to attack or counter temporarily, leaving it open to attack.
The optimal strategy is to prevent Calcabrina from forming in the first place, by quickly taking out the Calcas and Brinas. The player should use Focus three times with Yang, then use Kick to all Calcas and Brinas until they die.
If the player is intent on battling Calcabrina, its attacking power is crippled by the Blink status. Rosa can cast it along with Protect, and she should cast both spells as soon as the battle starts. Yang should be the main attacker, using Focus. Cecil can also cover his allies, as he has good defense and good HP.