Ok first get lv 30 then talk to gumbah (a child galka) in a house on the second floor of the bastok mines. He will tell u to go search in Palborough Mines to find a Dark Knight named Zeid. Zeid is located at ( H-8 ) on the third floor of the mines. go on the boat and when u get off a cutscene will happen. Zeid says if u wish to become a Dark Knight u must fill the sword's (Chaosbringer - lv 1 dmg 3 delay 666 DRK/WAR can use it) hunger by killing 100 monsters with the sword ( You must use the sword to deal the finishing blow). You must kill all of the monsters in the same zone. U can log out , zone , die all that stuff but a weapon skill does count. Once you have done that go to Beadeaux . When u enter there will be a cutscense with Zeid. He will tell u that u have fulfilled the swords hunger for souls. U are now able to change jobs to a Dark Knight.