Did you have all three of my maps running at the same time? If so, please don't do that again. Because my maps conflict with each other. And even more so than with some very large mods. They use the same files, but modify them differently.
I found the reason. I looked at the mod that prevents the AI from fleeing (completely useless on my maps, because the AI is already prevented from doing so) and it turned out to be the culprit. It clutters the console with a lot of errors in single missions like mine and makes all AI heroes respawn. Tested on my new map. So with it, the AI can buy back absolutely anyone if that person was killed on the map. This mod interferes with the AI much more globally than it seems. Judging by the file names, this is part of MegaAI and there is quite a lot written in the scripts that has nothing to do with fleeing.
Frederick and Orion were supposed to respawn, but only with their owners and in their cities. Reveran, on the other hand, is a one-time opponent; his AI is disabled, so when bought back with the anti-fleeing mod, he just sat in the cities and "delighted" you with his special ability to seek revenge. And he was bought back in a city where only Frederick is allowed.
Forget about 24k damage; let it remain a secret. Malassa must have buffed Railag.
Here are a couple more interesting facts: Godric is supposed to respawn in the first mission, but only for the blue player. I allowed it for some reason, although the AI doesn't get much benefit from him compared to any other level 1 knight. But Bertrand doesn't in the second, even for his owner. Thank goodness Wessel couldn't be bought back. Otherwise, it would have been even worse than with Reveran.
Well, it seems the answers have been found.
It clutters the console with a lot of errors in single missions like mine and makes all AI heroes respawn. Tested on my new map.
I was quite surprised. That such a small mod could have such a big impact on the gameplay - and it seems that this happened in all campaigns, not just yours, but also in Andrey_21's, where the AI also liked to pull pranks. And I didn't understand why everything was fine for everyone else, but for me, everything worked through a mess. In short, I'll remove all these bad mods, and even better, I'll reinstall the game from scratch, and in the future, if I need to play a campaign where the AI flees, I'll just use the console to apply the "shackles of inevitability" to them. (I was also amused that I was playing a very complicated version of both of your campaigns (yours and Andrey's), and still didn't complain about the hardcore difficulty, although some people were really struggling, even without the extra endless priests of Erebus
well, I mean, without their constant spawning).
Added 8 minutes ago
It just dawned on me why the avatar died from a single spell. Before casting "frost nova" on her, I hit her a couple of times with furries, which dealt the missing 412 damage; if you test it and hit twice with furries, they deal about that much damage. The rest was probably from the "deadly chill" special ability, which always kills at least one creature in the stack.
Apparently, this bad mod that prevents the AI from fleeing disabled the poor avatar's passive ability, which is why she died so comically. In short, I guess I'll have to replay ALL of your campaigns/scenarios, etc., because my playthrough was simply ridiculously ruined by this mod. I'll start again on the weekend.