I finished the Campaign. Wow, it's really good. I would add this, just like the Sandro Campaign, to the original game as official lore, after the Zehir Campaign, as a patch for the flawed storyline of the Heroes games.
When I was playing Heroes 6, I wondered - where are the Nagas? It seems like they didn't really disappear after the Irina Campaign, so where is the reinforcement for the Alliance of Fools? I understand that they weren't added because of the technical limitations of Heroes 5; there just wasn't enough time and resources. But Ubisoft also didn't find a way to incorporate them into the storyline - it's a pity (perhaps because Ubisoft is a terrible company). But this Campaign fits perfectly and authentically into the lore of the Heroes games. It's a small storyline, like 5 missions, but it tells a very small story, but at the same time it is so rich, with a large number of activities on the map, beautiful models of a whole new race, and the units are not repeated from Heroes 6, but they are made like the other races - with an "adaptation" to the time. New times - new army. And even the heroes are interesting in themselves, they really resemble the Naga heroes from Heroes 6.
10 out of 10, definitely. In terms of storyline, I like the Sandro Campaign more, it has a larger scope in terms of lore, but technically - this one is the clear favorite. It's scary to imagine how much effort was put into it; even the final credits glitched and didn't fit completely into the dialogue window (or maybe it's because of my square monitor). As I understand it, a sequel is not planned yet? In my opinion, it perfectly describes how Fenrig figured out how to find the artifact.