Added after 19 hours 57 minutes
In general, everything resolved itself! I left Igor in his fortress and went to finish off Cornelia. I teleported to her nearest fort, defeated 101 Angels! and took "Mournful Song", the best artifact for a human mage, it gives +5 magic power to Light and -10% spell cost. And just as I was about to attack Cornelia, she runs out of the castle and heads sharply down towards the very bottom castle in the left corner. Her army without a hero seemed like an ordinary warm-up! AND IN HER CASTLE, THERE IS AN OPPORTUNITY TO UPGRADE RADIANCE CREATURES!! OH! This is indescribable! Golden Radiance creatures!!! So, Cornelia leaves another part of her army in the fort along the way and DOESN'T REACH THE BOTTOM CASTLE, where on the second turn, my main hero teleports with his entire main army! And remains in the built castle! Cornelia has nothing left to do but attack! Defending in a castle is a fairy tale! On the first turn, "Stop Time" on the enemy archers, and with my archers, into the TOWER!! Radiance creatures to the very gates! The rest of the army to block! The griffons that flew into the castle got hammered by the knights, spearmen, and vestals! Radiance creatures ANNIHILATED THE ENTIRE ENEMY ARMY! And with the support of archers from the tower, Cornelia didn't have a single chance! I lost exactly 5 spearmen. Igor surrendered without a fight))) no, he did resist, but golden Radiance creatures + summoning light elementals! THE GATE to the Dungeon did not open!! HOORAY! Now I'm clearing the surface, defeating LEGIONS! And upgrading "Mournful Song". The praised Cyclops, who guarded the entrance to the Dungeon, met me with a friendly company of 132 happy barbarian faces! I defeated them without losses)))) The map is incredibly interesting! I've now saved before entering the Dungeon!