Dark Knight is a job in Final Fantasy Tactics: The War of the Lions. It has abilities that focus on delivering damage to opponents using the darkness to drain their HP or MP, and also can attack sacrificing their own HP to inflict more damage. It costs 6,900 JP to master.
In the original PlayStation version, Dark Knight was Gaff Gafgarion's exclusive Job. His job has since been renamed to Fell Knight. While his two abilities, Shadowblade and Duskblade, appear identical to Sanguine Sword and Infernal Strike, Gaffgarion's variants are slightly more powerful.
Dark Knight is the only standard job in the game, other than the Knight, able to wield Knight Swords. They also have access to their own exclusive weapon type, called Fell Swords, which can only be obtained in Melee and Rendezvous.
The Dark Knight possess the highest attack power of any standard job, it is also the only job in the game with 0% C-EV.