Finally, I completed this mission on veteran difficulty, version 1.6. After the first battle with Gilraen, I went to the northwest city through zombies and earth elementals, which I defeated without losses thanks to "Phantom" (obtained as a bonus in the previous mission). In the first week of the second month, I captured the city, built a castle, and gained an elf bonus. Then Gilraen attacked (difficulty: high). The beast almost destroyed my entire army, but I still won:cool:. Then, an additional hero brought me reinforcements (I was building a demon castle). After capturing the northeastern city, the mission turned into searching for various upgrades and defeating minor heroes. Then I captured the southern city, and the mission ended. Good luck to everyone in completing it!