I abandoned playing through the campaign in the original game because it was too difficult, even on "Warrior" difficulty in this mission. Version 1.0. How do you manage all the Elven cities? And the week of druids… also makes it hard to relax. In general, only the Chosen ones can complete this mission.

In 1.0, it's just terrible; even "Warrior" difficulty is harder to complete than "Hero" difficulty in 1.6. I managed to complete this mission, and with great difficulty, I completed the second mission for Faelan, but I couldn't defeat the strongest demon, and I failed completely on the fifth mission due to an unseen number of Necromancer armies. It's better to give up on this version.
But in 1.6, this mission is completed without much difficulty, even on "Hero" difficulty. The other day, I started replaying the original campaign, and I completed this mission in just over a month using my favorite demonic army. The difficulty is the highest, as I said.