Around level 30 of my first playthrough with demoness I suddenly had a thought : hm, this is going quite smoothly, not overly difficult, don't you want start over with some challenge? Truly idiotic thought of course, not knowing what to expect, how new spells work, new skills, new items, what are quests, not using scanner. But I started anyway, with single black dragon, to see at least how far I could get in the game. If you ask why single black dragon, this challenge is going back to Armored Princess days and of all the challenges is the closest to my heart. I truly recommend it to KB veterans.I wanted to try it in new environment and measure my progress for now by either hitting certain impossible fight or maybe number of fights (= no loss fights). So start with vampire, lose some troops in Shelter and Whitehill fights, then kite for archdemon in helvedia, and finally get 1 black dragon from Shelter and start the game properly.
Now, you probably hear it here first, single black dragon army with mage is capable of winning every single fight in the game.

Yes, that includes final battle, 3 whitehill heroes, obelisks in Aralan with summoning towers with 60000hp, you name it. And apart from using about 4 Ancient Knowledge I did need any other wanderer scrolls, there is no need for them.
After some experimenting, here is the ultimate combo = super high intellect + nature call spell. You still have to be clever - casting fear + nature call, nature call 1 + target, nature call 1 + nature call 3, maybe some sheep etc, flame of passion is pretty much compulsory. I can go in detail here if anyone's interested about tactics, equipment, skills etc.
Some pictures here:
picture 1 = maxed out end-game royal griffins at intellect 109. Who wants to fight?
picture 2 = final battle. Since I usually overwhelm the battlefield with many summons which do the fighting, black dragon does not even appear on the my troops listing; can be seen on the battlefield though.
picture 3, 4 - final scores. 215 losses. Some troops lost in early Shelter and Whitehill battles. Then there are two chained fights - one in Helvedia - knight hero followed by demon hero, and then in Baraz-Gund - Kings castle. Due to Puppeteer skill I always carried over some weakened summoned stacks which died in second battle.