Skull of Shadows (SoS) is a Polish mod that replaces all the factions.

I thought it was for Heroes, but it's based on Dis's work.

But the map is good (at least those who played it liked it). I'm currently working on a map for Heroes, a single-player map for Necropolis and Markel (my Markel, not the famous old intriguer, although the model is the same).
P.S. Is there a mod that replaces the visual of the Necropolis castle with the Necropolis from Heroes VI?