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Very similar Walkthrough to Boris_K (post 103 of the topic).
Version 1.6. Difficulty: "Warrior". No glitches encountered.
In the Castle, Wingael was sitting with a huge army (the capital was retaken with almost no losses). Fedor modestly left with 9 emeralds and ~15 Light Horns to attack the second Elven Castle (without any problems).
The purple faction didn't attack at all :( To make them attack, I had to summon half of the army with Fedor, only then did Deidra come for the Lycans.
After capturing the second Castle, I fed Ilfina with suitcases (there were a lot of suitcases on the map) (up to ~18 level + Light Horns = a killing machine), because Fedor reached his maximum level very quickly.
By the way, both liberated heroes didn't level up (it said that the maximum level was reached).
In general, it was an easy playthrough. The good magic in the Castles helped - teleport, summon troops, portal to the city, resurrection.
PS I remembered a glitch - when I tried to put Wingael in the Castle garrison, the game crashed on the opponent's turn.
PPS And I also tried to level up Fedor with the "Skill Wheel" (3.0 from Google), but it turns out (if I understood correctly) that the skill wheel of this version doesn't work for leveling up the "Skill Wheel" in 1.6 (the list of skills and perks for leveling up the Elven "Skill Wheel" in 1.6 is completely different) :(