In general, our city will be comparable in strength to Dungeon. That is, it will have very strong magic and sturdy, powerful units, making it a quite strong castle, but it won't be out of balance (I might be revealing some confidential information now). Testing has shown that Haven and Conflux (recognized leaders) can easily defeat Necropolis, and there are difficulties in battles with Inferno. Now about the creatures in Heroes 4: they are some kind of mutants. In general, the ability will be implemented, but on a monster that only remotely resembles this creature.