And how is the transparency of ghosts implemented? Is it some kind of effect? Well, you could create a faceless ghost by combining Heroes 6 and 5... You could take the ghost from Heroes 5 as a basis... but instead of a skull, use that kind of "stretched mask"... like in Heroes 6... but there it looks very much like a theatrical mask... I would rather make it "more stretched" so that the bump of the nose is visible.
One line in the material is responsible for transparency; usually, we write AM_ALPHA_TEST there, but there are also these settings:
AM_TRANSPARENT - this is the setting for the ghost; as you can see in the corresponding screenshot, there is a problem - a transparent texture is superimposed on another transparent texture (like a face on a hood), and it turns out to be an ugly spot. I once made a ghost and, frankly, I got tired of erasing all the textures of the folds or the reverse sides of the clothing on the sleeves, hem, and shoulder cape.
AM_OVERLAY_ZWRITE - this is from the Genie-Vizier; it's a strange thing; you can see that there are holes in the hem where the polygons overlap... the Genie has the same bug; he has piercings on his nipples, and from some angles, you can see that the square creates a hole.
AM_OVERLAY - a strange thing; it's as if the unit has been turned inside out