Kostya said that rebuilding in h3dm1 is disabled (there was a discussion of the rules on 112). By default in hw_rules in Mage Guild on the SoD mirror, there is control in one of the guilds.
The situation is simple - I have 2 heroes with all air, Kostya has power and a chance to build up Mage Guild 5 in one of the 4+ cities and get air control there. During this time, I devour all ownerless boxes, cities on the map, and artifacts (according to Cobra's rules). And the demon as well, since my money flow is decent because I have more cities.