Need help with playing against the AI!

Can all creatures be turned into undead? To be honest, I didn't know about this transformation.

Of course, with the help of the "abandoned castle" building (or something like that).

How do you like the Stronghold? Fury adds strength and defense, what do you think?

It's a strong faction, but I think it's not the best counter-faction against the Elves. But, like any other faction, it will win if you act correctly.

And a friend said that Inferno and Necropolis reduce the luck of opponents, is that true?

You can reduce luck with special artifacts (there's a ring like that), skills (deadly misfortune), or creature abilities (blood-eyed cyclops). It's not related to a specific faction.