Test. Which Castle from Heroes of Might and Magic III suits you best?

...now guess!

So, your city is Necropolis.
Necropolises are ruled by the undead, who have seized once-living cities. Their allies are necromancers and Death Knights. Many of the Necropolis's warriors can weaken the power of the enemy unit. This gives them a quick advantage over an equal or even superior opponent.
I didn't doubt it for a second!