Do you have a couple of questions about mentoring?

No, banning for multi-threading is bad form, and it's not written in the rules either.

You create a folder called MyMod; you extract all the required mods into it, if these mods don't overlap in terms of the final xdb files (for example, they modify the same hero's file). If they do overlap, the program will ask you if you want to replace, not copy, or copy with a different name. Overlapping mods are incompatible, and at the points of intersection, you will need to choose which mod is better.
But now, all the extracted mods (with the unchanged directory structure) are in your folder. Now, right-click on this folder => Send to Zip archive. You get a zip folder. Rename it to .h5u manually and put it in UserMods.

How permissible is it on the forum to use ready-made mods created by other people in your own work? I just want to create a mod collection for unique hero appearances. Essentially, without creating anything new, but by compiling separate mods into one convenient package.

Ahahaha). So, you just take it and change the archive extension? Meaning mods are just regular archives with files?
And will there be any problems if I put the .h5u mod files from the usermods folder into an archive and then convert it back to .h5u?

Incidentally, another idea has come up... I understand that it probably doesn't concern you, and you might not even know. But why not ask? Maybe someone will like such a mod if I manage to create it.

Idea: Create a mod that replaces the music in the game. It turns out that you also need to create directories and put the music in them. But where can I create the .ogg extension for the music, and will it be affected during the transformation?
The mod should be created according to the principle described above with usermods (but how does the game recognize a mod so that the files from the mod are used with priority compared to the standard music files?) or should I just create an archive with directories and let people simply replace their music with these files?

P.S. Is there a model of Biara in the folders anywhere? And how can I make this model be used for Jezebeth? Should I write the name in the model - "Inferno - Jezebeth.h5u" or should something inside the file itself be changed?

Again, thank you for the answers.

Added after 1 hour 51 minutes
Ugh. I tried to make a mod. In the end, I did as it was written, but the game doesn't start. To understand, I opened one of the .h5u files with WinRAR. As a result, I realized that you can't put .h5u mods into one .h5u mod so that it works.
It turns out that you need to open each file manually. Extract the files from it, and then combine all these files into an archive and then convert it to .h5u? Or do you need to somehow specify/insert these files somewhere? (I just don't understand how the game reads and understands where to use the files from UserMODs)
Is there a quick way to extract all the files from a bunch of small .h5u mods to combine them into one global mod? Or is it only possible slowly, one by one, through the archive?