An interesting situation arises. You say that the Black Dragon is the best unit and that if you have it in your army, it will easily defeat everyone. I must disagree. Hydras, with their 250 HP, high damage, and splash attack, are just as good. Also, those cursed Djinn-Ifrits are interesting units. I like them more than Nightmares. What's interesting is that their shield is completely unpredictable. A General's cat-like reaction to Hydras or Ifrits, and suddenly, you become invincible. Of course, a mass buff on Hydras, plus their high damage, is much better than the Black Dragon's attack, and they are also immune to blessings. And in general, if you apply Accuracy to Titans and place them on a tower, they will easily take down any dragons, including Black Dragons. The hardest thing is to capture a Castle with Chaos, of course. Imagine you have 5 dragons, and you've been saving up and collecting them for 5 weeks, and then 30 monks under a blessing, plus 250 archers on a tower, also under a blessing, instantly kill your hero and damage dealer, and suddenly, the Nightmare's terror and our mass failure are easily neutralized by the enemy's priest. The result: we were completely defeated.