The most challenging campaign.

Ah, is this where you have to find dragons at the obelisks? Yes, it was a difficult mission. You had to accumulate a certain number of dragons to complete the mission, right?

You need to collect dragons in two missions - 2.3 and 5.2. In both, collecting the dragons is the easiest part. The most difficult part is dealing with the enemies.

In 2.3, in version 1.5, more than 100 dragons joined my hero, but I only needed 20. I'm not sure if all the dragons counted. Both regular and upgraded dragons joined. I saved them all.

In mission 5.2, collecting dragons at the obelisks is also not a problem. However, capturing 3 cities is really difficult. Deleeb is especially dangerous. IMHO, this is one of the most difficult missions.