If you are in Citadel and you are refering to the DKs there, then try this : On the first turn of the coridor in Citadel turn right. There is a room there with the next Battlefield key which unlocks the second dungeon. Sneak to that room and visit Battlefields. DKs are very hard to kill so you will need all the xp you can get. Use pause key very often and try to have as many portions as you can. You can fix your points with strenght etc the next time you level up. I got all DK with one handed weapon and spells.