Well, using the console and magic, I finally finished this scenario. I completely forgot that if you reload a save with a broken combat script, the latter will stop working entirely and the battle will end. So, I did eventually destroy the demon. But my torments didn't end there...
I had absolutely no idea how to get to the mage or where the demon's other town was. I didn't understand how to get past the heralds or where the Tear was. Using the power of the console, I opened the map and found a Necropolis with a key-bearer of a suspiciously magical color. The thing is, there's absolutely no way to get there—no portals, nothing. Just a broken bridge. So, I stood on the very edge of this bridge. It turned out that the trigger zone for repairing this bridge is on the very edge! Tiny! I didn't bother repairing it, I just teleported there using a cheat, wiped out the Necromancer (for some reason under the demon's flag), and gained access to the mage. I killed him; there wasn't even a cinematic, but the quests were marked as completed.
Still, I needed the Tear. I found its location. It was behind the heralds. I just walked straight at them and suddenly they let me pass, lol. They could have warned me... I dug up the tear, built it, and headed for Holyflame. If Dominic attacked it, the animation for removing the barrier played and nothing else. If Hafad did, the animation was skipped and the battle began. Hafad just had a bare garrison, while Dominic had a fairly weak army of an archbishop. Everything was going like clockwork, but then I realized I was doing something wrong because an error appeared in the console saying the quest doesn't exist.
It turned out that first I had to go to the cemetery and speak in a known language with a weak Alaric, and only then go to Holyflame. Except the scripts fully allowed doing it the other way around and breaking everything.
After doing everything properly, I made a bold move and returned Lightwood to the blue player via the console. Hafad turned into a Necromancer, finished off Alaric, and again—an error in the console. And no, not about Lightwood. About Hafad himself. Saying he is already out of reserve. Meanwhile, another archbishop appeared in Lightwood.
I decided to just attack the town with Hafad and everything worked as intended. Two battles, then the finale. By the way, during the transformation, Hafad was given 1200 dragons in two upgrades of 600. This was enough for all subsequent battles, including the final one. Everything would be fine, but I was given two dozen Death Knights and a hundred heralds.
In short, the mission was won with victory and other laurels.
Nuance: the second battle with the archbishop is always easier because the fodder there is fixed. Consequently, Dominic is just chilling compared to Hafad. And in general, why is there a double battle in the town at the end if only Hafad is fighting?
Another nuance: the avatar is weak. 400-something HP at the maximum 30th level.
Third nuance: the first time during transformation, the Hafads could exchange armies. In the second similar case, this didn't happen (I reloaded several times along the way).
Fourth nuance: give necro-Hafad all the darkness spells at once. It's logical.
Otherwise... the map is quite beautiful, except for the shadows in the underground. They behave strangely, especially for the dwarf. The lighting needs some work. There are cool ideas like small units in towns and thematic objects like a druid with stats or a rune priest. But they are poorly readable at times. The first monastery sends its regards; I ignored it for about three in-game months. The cinematics are decent, especially for the first map, but the dialogues have some issues. At the very least, the number of exclamation and question marks should be reduced to what is accepted in polite society: no more than one at the end of a sentence. Additional ones don't make a phrase more emotional. The plot is confusing. Or rather, it's as simple as can be, but a lot is presented as if the player has seen these characters a hundred times, not for the first time. And isn't it a bit too early for Alaric to be reborn under his own name?) Plus, the demons weren't planning an invasion then: their plan with the Dark Messiah was succeeding. Unless it was just to distract attention. The archbishop is a carbon copy of Dominic from the Unicorn Empire campaign, except he took the robe from Vessel from my map, and has his own icon, uh-huh.
Overall, the map is not bad and even strong for a new mapmaker, but there are more bugs here than is customary in the modern gaming industry! They ruined the whole impression. And the gameplay is passive. The enemies do almost nothing, but they have tons of fodder and stats.
5 out of 10, plus a point for the inheritance to RedHaven)
Added after 4 minutes
Oh, one more thing. Upgraded heralds can be raised by necromancy, but ordinary ones cannot, and upgraded heralds don't exist anywhere else except through necromancy. Also, they appear in the cinematics. It feels like an oversight. Furthermore, according to the description of the Death Knight building, heralds should be recruitable there as well.
Added after 47 minutes
Oh, I just remembered, the druid recruitment building has no icon in the caravan menu. It would be nice to script something. For example, an icon of a similar building from an elf town.