The Black Mushroom Men completely reversed the tide of battle the first time they appeared on the battlefield.
Rather than their extensive use of firearms, their much tougher bodies were the most important factor in their success.
Their usual tactic was to advance through attacks from electromagnetic wave weapons, then bombard their targets with recoilless rifles and rocket launchers.
Against these crazed, powerful enemies, even the heavily armored Felguards hiding behind cover could not withstand such a ferocious assault.
The Black Mushroom Men had already led the Plant Army through the city's outer defenses.
Had Doctor Zizi not prepared for this long ago by building extensive fortifications inside the city, it would have been flattened in a single push.
The strategy of using fortifications for successive layers of defense would grow increasingly effective the deeper the attackers advanced into the city.
That was because this city was different from ordinary, flat cities.
It was a three-dimensional city that combined light industrial, heavy industrial, and residential districts, the sort that existed only in people's imaginations.
The bottom of the city was the heavy industrial district, used to manufacture all kinds of metal parts and assemble large war machines.
The middle of the city was the light industrial district, a cluster of industries whose products covered consumer needs such as food, clothing, housing, transportation, and entertainment.
Because demons had rather unusual needs, the light industrial district was not particularly large.
The upper levels were residential districts, where many demons lived.
However, demons did not have high standards for their accommodations.
Many demons lived in the bottom and middle levels as well.
The quality of their living environment was never something demons considered.
They therefore did not care whether the city was too filthy or foul-smelling.
Sewage flowed through the streets, and garbage