Walkthroughs for custom maps.

Do you mean Zemsta Mutare or Seven Seals?

"Zemsta Mutare". Only the final part is confusing, but everything before that is actually passable.
By the way, here Wyst, on the 32nd day, abandoned the Walkthrough, got stuck on one of the last garrisons, and started playing Wayfarer.

I'm currently playing one of the maps from my collection. At the end, you have to defeat the hero - the Dragon Mother, Madre, with 4x99 and thousands of dragons in her stack. I can't use hit-and-run tactics because the condition is the hero's death. After a couple of attempts, trying different spells and changing artifacts, I gave up, uhm, with a message to the nasty guy: "Go to hell, Madre!". I'll upload the save, maybe there's a way to defeat him...

Let's have the name, link, or the map and save. We'll take a look.
By the way, for hardcore fans, there's another challenge (I just came across it):
Game of Thrones meets Dragon Age

Your ultimate goal is to defeat everyone, which on this map is nearly
impossible, as even on easy this map is extremely hard.
I still haven’t passed it...

Great: "I created a super-difficult map that I haven't been able to complete myself, so now let you guys suffer!"
:D
Basically, at first glance, the difficulty of the map lies in the fact that the player starts with one Tower, and 3 out of 6 enemies have "countless" cities from the start, so the epicness of the battles is expected to be significant.
Some of those who responded there (including Valery himself), however, have completed it, but read the notes first: it is desirable to disable Flight, Dimension Door, and it is very important that Slow be available in the guild of mages (so it is worth checking the starting save immediately and regenerating the layout if Slow is not available).