Jinx

Jinx (バッドタイム) is a recurring ability in the series. Its effects vary per game.

Final Fantasy X
Jinx is an ability found on Kimahri's portion of the Sphere Grid. It costs no MP to use, and lowers the enemy party's Luck, Accuracy, Evasion, and critical hit rate by one to five points.

Final Fantasy XIII
Jinx is the only Saboteur auto-ability which increases the duration of all weakening and jamming spells on the opponent whenever a new ailment is inflicted.

Final Fantasy XIII-2
Jinx is still the only auto-ability accessible by Saboteurs and little to no changes have been made. It is available to Serah via normal leveling methods, but if the player infuses a Saboteur monster with a combined level of 99 Synergist, the Saboteur will learn Jinx. Noel however, cannot learn it at all.