To unlock the character's corrupted form without replaying the entire campaign.
In these games, characters like undergo dramatic transformations based on the player's choices. The title "Princess of Defeat" (or "Princess of Corruption") refers to a "Law" or "Chaos" path where a heroine is captured and magically or physically altered by the antagonist.
Fina is often depicted as a high-ranking royal or divine warrior.
This specific "File" or status refers to her "fallen" version after being defeated in battle. In this state, her loyalties, powers, and physical appearance change to reflect the influence of her captor.