Elemental resistance debuff

Elemental resistance debuffs are a series of status effects in Final Fantasy series. They reduce target's elemental resistance.

Final Fantasy XIII'
The Saboteur ability Imperil reduce all of target's elemental resistances by one class.

Final Fantasy XIII-2
Imperil returns as a Saboteur with its effect mostly unchanged, bar a minor Wound effect.

Lightning Returns: Final Fantasy XIII
When Lightning staggers an opponent it may acquire an elemental resistance debuff if it is programmed into its stagger debuffs.

Final Fantasy Record Keeper
Some Soul Breaks can reduce targets' elemental resistances. Elemental resistance goes as follows: Absorb → Immune → Resist → Normal → Slight Weakness → Vulnerable. Each of these resistance categories is further subdivided into multiple levels. Enemies can have multiple elemental resistance debuffs simultaneusly and each debuff has three levels of debuff and more level further increase elemental damage received.