Finally finished the fifth one.
Structurally, it's very similar to the second one – very simple neutral creatures and extremely unpleasant final battles.
I completed all the quests in the underground in 2.5 months; perhaps the time limit for this part of the mission should be reduced.
I thought I could quickly rush the ending, but in the Celestial Gates, I was met by five Mutants with a ton of troops and absolutely insane resistance values. On top of that, a +20% HP week rolled, which made things very difficult for my Chaos heroes, Shadia and Railag. The most I could manage was 4 won battles, after which Sigrif had to fight with literally his starting weak army, which I couldn't quite pull off.
I spent a couple more weeks gathering additional troops from the map and discovered 2 bugs. First, the quests to burn down huts and clear out the utopia automatically fail when you go to the surface (the quest for the Tear also fails, even though it was already marked as completed). As a result, they cannot be completed, although all the scripted battles there work correctly.
Quests

Second, completing the prison quest gives you troops from the Order faction, not the League.
Prisons

With everything gathered and the armies redistributed, things became easier. Shadia handles Phantom Wolves and can ignore archers with her special ability. Ilaya is a very strong hero, but her opponent casts Vengeance constantly – you need to rush as quickly as possible. Tralsaya has a fairly easy battle; a very powerful hero emerged on Darkness. Railag is still weak; almost 60 skill points combined with Attack and Defense skills don't give Chaos any chance with such high resistance values, so I have to abuse passing the Tome of Darkness between battles. Sigrif also has a difficult opponent + I forgot to activate Urgash's Power, but overall it's okay.
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Final battles]





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434 days for the entire campaign (415 if I could somehow finish the battles earlier).
Overall, I have mixed feelings about this rework. On the one hand, the PvE has become very simple; on the other hand, most of the final battles with heroes have become a real challenge, not just passively running around with Fury units under Vampirism. The pace of the campaign has significantly increased, but some things are still designed as if for the old timings and are either broken, like the castles in the 3rd mission, or have become almost a useless part of the gameplay, like the scouts in the first or Deleb in the second. I didn't encounter any game-breaking bugs, which is also a big plus. In general, if the rework is aimed at updating and making it more convenient for players, then the result is скорее positive, although there is still work to be done.
Thank you very much for your work in any case!