The castle of your dreams.

Castle of a new faction (half-demons, half-undead). The strongest unit is the God of Fire.

You need to play Heroes 4 more!:D

I took a look. In principle, all the castles are designed in the style of a certain culture, but there are no similarities or even hints of Slavic culture!

But we also have a rich mythology! How about this idea?
I would play it!