Walkthrough for the "Tribes of the East" expansion.

I don't understand anything... I gathered an army, transformed everyone into Necromancers, and went to a castle with 134 dragons, etc.... but I still get beaten... the troops, except for the flying ones, just stand at the castle walls and can't get through, and they are slowly being destroyed... where is that tear, I think I'll have to replay... why bother gathering such a large army, golem... hmm... I've already explored everything... damn, either I'm stupid, or something else.