The most challenging maps for you.

In Heroes 3, it has become a common occurrence that the computer has no chance of success (under reasonable conditions, of course), and you can do whatever you want with it. When a player comes to this conclusion, they can confidently be considered no longer a newbie.
But for now, we will read something like this:

an incredibly cool final boss

So, I think the author decided to make Salamandre invincible.

and the battle will be won on the first try, then, unfortunately.