In all KB games I always use black dragons - one of the best units ever. Of course you gotta be careful not to lose a single one since they're rare, especially in WoTN, but their fly'n'fire ability is absolutely hilarious, especially when combined with top level greasy mist.
But truth be told I never found any use for any other 5lvl unit in WoTN. Trolls, jotuns and chieftains are great in early stages, if you can find some, but then just meh. I dropped ice dragons after few fights as well and other dragons aren't nearly as good as blackies. Archdemons never really clicked with me, they do only average damage and their "Halve" ability is useful only in the first two rounds, where the enemy ranks are still numerous. But for that they have to teleport right in the middle of huge enemy crowds and get quickly massacred without any hope of ressurection. Cyclops are fantastic all around, only they were always the rarest unit in all my KB games and they could never keep up with my leadership. Did I forget anything?
By the way, fair warning - if Prince Consort is selling black dragons, buy all of them from him while you can and store them in a safe castle, which means basically anywhere but the main continent (and that goes basically for all human units you like to use; some of them you can buy in limited amount later but better safe than sorry). Do not store anything in Greenwort or Arlania castles while you work for the Prince. I REALLY could have used that advice myself
