Mod

Hero classes:
Warrior - Prince
Mage - Warlock

Added 5 minutes later

The chimney isn't needed because the Necropolis already has one. The Kremlin is the Graal. The Guild could definitely be designed like that.

Added 5 minutes later
However, you can come up with another Graal...

Well, the Graal is usually just one building... The Kremlin consists more of walls, so it looks more like a Castle. The Graal could be, for example, the Cathedral of Vasily the Blessed next to the Kremlin...Younus - in all battles, any Hero initially casts an expert bless (blessing).