Auto-translated
You don't need to collect Moon Discs; you'll get the Ash Tear after completing the quest related to the dragon. I completed the mission easily without any losses on the medium difficulty level, playing as a Warrior, using the skills Path of Blood, Restoration, Healing, and Drain. The best skill for this mission is definitely Reinforcement. Sandor spends 2 days mopping up all the attackers, then 5 days exploring the map, and so on for several weeks. With the second hero, you can gather an army across the map. The only thing I didn't understand was where the end of the mission is; I went to the forum and read about it.
Message from Pobeditel:
To complete the mission, you need to defeat Mukao (wait for him in the city or fortress). He will arrive after 3-4 heroes, after you have gathered all the veterans. Before that, I advise you to complete all the additional quests.