I don't know why everyone is so upset about the second mission. I started it casually, and even the initial scouting took only a little bit of brainpower. Then I went underground, gained some experience, captured mines, and generally got settled. Meanwhile, Markel set out to sea, luckily guessing that he needed to sail west. He found the Sphinx (failed the test, laughed at the 999 Phoenixes), reloaded the save, passed the test, took the hero's armor, and generally got himself sorted out.
Then an Orc arrived, but my army was already too strong for him, so he retreated (screenshots 1, 2) across the sea. I managed to get the old man to Srando, cell by cell, and pass on the army. The Orcs retreated home without a fight. I started clearing out the underground and then a Demon appeared. I REALLY shouldn't have given him Pillaging. I replayed, ran to the castle.
THE DEMON ALSO RETREATED and went to the Orcs. While I was cleaning up the surrounding territories and the underground, the Demon had already thinned out the Orcs considerably and was left with a meager army (4). The Orcs also took a beating, and half of their army simply died. At the same time, I already had a legion of undead (5), while the Demon had only about 50 demons in total (6).
There's not much more to tell, the Orcs huddled in the corners from my huge army, and I sat for an hour, maybe even two, just clearing the islands of the remaining Orcs and going around the buff spots. Special thanks for the mentor.
I especially liked the storyline and the Eclipse element; it's really well done, even better than the original Campaign, but the technical part let me down; the enemies ended up defeating each other!
https://imgur.com/a/NXs4HCp - screenshots