Two heroes, Wulfsten (a dwarf) and Zehir, start in the Dungeon. One of the main objectives is "Wulfsten must continue to fight." The objective itself states: "Wulfsten must not only survive but also gain strength. Otherwise, he will not be able to help Zehir in the assault on the Claw."
I understood this as a quest to level up the dwarf. Since Wulfsten cannot leave the Dungeon, I had him kill and capture everyone he could within the Dungeon. The quest was not completed. Now, only Zehir can go to the surface.
But what do they want from the dwarf? This is a main quest; without it, the mission cannot be completed...

The essence of the mission is that Zehir goes to clear the surface, while Wulfsten remains to guard the Dungeon from the yellow faction. You can quickly go through the Dungeon with these two heroes, and then send Zehir to the surface and leave Wulfsten to guard it. On the surface, Zehir searches for the meeting place with Arcat, clearing the area and collecting artifacts, including the dwarven set, which can be given to Wulfsten for the final battle. There, in the Dungeon at the end of the mission, on the mentor, Wulfsten builds the necessary build. Near the summoning place of Arcat, Zehir will have his last battle. The mission is not difficult; only the yellow faction's raids are annoying.