I still see Lancer as the best current class to create Dark Knight out of. The lance curves into scythe to give a FFXI throwback. They already have a lifestealing ability in Life Surge and all kinds of DPS, and the jumps all get replaced by the Drk job skills. Their skills already sound Dark Knighty in Chaos thrust, blood for blood, doom spike... Make blm the req sub and marauder the other cross and done. Perhaps even tweak the marauder skills that have life steal to also be cross class. Souleater lvl 30 job skill and other cool things from their.