[calmon]

Sounds like a bug for me.

The whole dragon master thing is very misterious. You need to research level 8 to get dragon master, you need a nature 3 mage and this one need at least 2 earth, water, fire or air magic to cast a summon drake/wyvern spell. And all you get for this tough requirements is 3 of a very useless creature. I did some tests, i wasn't able to get a simple independent province with 12 cave drakes which cost me 32 gems with dragon master or 96 without. Very pointless! Even with the balance mod (which do it in a research level 3 category).