As a mage known for his vast knowledge, the Great Mage naturally knew that these monsters in front of him were ghouls.
It wasn't just the corpses of humans that could become ghouls. Basically, any intelligent creature could become a ghoul as long as the conditions were right.
As a Great Mage, although he wasn't a necromancer, he was very clear about some basic necromancy knowledge.
When the corpses of humanoid creatures were corroded by negative energy in an area rich in negative energy, there would be several different outcomes.
The corpses of ordinary people, under the corrosion of negative energy, would rot faster and quickly become a pile of bones.
The corrosive effect of negative energy on bones was far inferior to that of flesh and blood. Therefore, bones could exist in negative energy for a long time. During this process, bones would undergo some miraculous changes under the influence of negative energy. In the end, bones would become a kind of negative energy substance.
Generally speaking, negative energy was harmful to most substances. It would accelerate the decay of flesh and blood, wither plants, and cause metals to decay. However, negative energy wasn't harmful to everything. For example, some viruses and molds would become very active in negative energy environments. Some wood and rare metals produced in the Underdark would undergo beneficial changes in negative energy.
These substances that would undergo beneficial changes in negative energy were negative energy substances.
If bones that had become negative energy substances continued to soak in dense negative energy, they would become stronger and stronger.
Of course, no matter how strong they became, negative energy oriented bones wouldn't suddenly become undead skeletons.
There was another prerequisite for the creation of undead creatures, and that was that the creature's soul didn't leave its corpse after death. In the process of the corpse becoming negative energy, the soul would also be corroded by the negative energy, eventually causing some kind of qualitative change. Under the influence of negative energy, the soul would combine with the corpse of negative energy and become an undead.
This was the process of the creation of undead skeletons.
The process of the creation of undead zombies was similar, but generally speaking, the corpses of zombies were relatively strong creatures when they were alive. Their flesh and blood were stronger and more resilient than ordinary creatures. Under the corrosion of negative energy, the rate of decay would be slower, and they would exist for a longer time in negative energy environments.
The flesh and blood of creatures were the same as bones. When they were soaked in negative energy for a long time, they would turn into negative energy.
If a corpse could completely turn into negative energy before it completely rotted, then it had the potential to become an undead zombie.
Ghouls were the perfect version of undead zombies.
When a corpse was strong enough, it could survive in a negative energy environment for a long time without rotting. If a corpse completed its negative energy transformation before rotting, it had the potential to become a ghoul.
After a long period of research, the necromancer discovered that there was a prerequisite for a corpse to become a ghoul, and that was that the corpse had to have gone berserk when it was alive. This was especially true for the corpses of warriors whose physiques had gone berserk. They were the easiest to turn into ghouls.
Ghouls were undead creatures that had preserved most of their bodily functions when they were alive. Their bodies that had been converted into negative energy were as agile as when they were alive, unlike zombies that had lost most of their bodily functions due to decay. Even if they successfully converted into negative energy, their bodies would still become very clumsy.
Not only did the ghouls retain their strength when they were alive, but during the process of negative energy conversion, their bodies became as thin as firewood, but they were also extremely tough. Normal swords and sabers could hardly hurt them.
Due to their incomparable strength, their bodies were thin and their weight reduced. They also didn't have any armour to hinder them, so ghouls had terrifying agility that they didn't possess when they were alive.
Their hunched bodies ran like the wind, and they could jump seven to eight metres high like frogs. Their sharp claws that carried the terrifying virus could even tear through normal steel armour.
Ghouls could also consume fresh flesh and blood to obtain more negative energy, allowing their bodies to quickly repair themselves.
Because there weren't many places where negative energy gathered in the prime material plane, natural undead were rarely born.
However, there were always exceptions.
The area around this arcane tower was one such exception.
Due to the imbalance of energy in the arcane tower, the surrounding tens of kilometres of land had been polluted by negative energy, forming an extremely large area of negative energy.
In this area, the corpses of every dead creature would be invaded by negative energy. Most of them would turn into white bones of negative energy, and a small number of powerful creatures would turn into corpses of negative energy that would not rot. These corpses were good raw materials for necromancers to create undead, but without external intervention, these corpses would never become undead because they did not have souls.
Normally, when a creature died, their soul would leave the body. Without the anchor of the body, the soul would be pulled into the underworld by the power of the world. A corpse without a soul would never become an undead.
However, there were always people in this world who, for various reasons, had their souls lingering in their corpses after death, unwilling to leave.
If this happened in a normal place, there wouldn't be any negative consequences. The power of the world was incomparably vast, and any soul that didn't want to leave would quickly be pulled into the underworld by the power of the world.
However, if this happened in an area rich in negative energy, there would be a chain reaction.
The soul that didn't want to leave would be affected by both the negative energy and the corpses of negative energy. In the end, it would combine with the corpses of negative energy, and thus, undead creatures were born.
Undead creatures were also known as undead creatures because the death of creatures was related to the invasion of negative energy. Undead creatures were creatures of negative energy. Negative energy was not only harmless to them, but it was also beneficial. Without the invasion of negative energy, undead creatures would never age or die. If there were no external interference, these creatures would naturally live much longer than humans.
After thousands of years of accumulation, a large number of undead creatures had gathered in this area of negative energy.
Among them, there was naturally a large number of ghouls.
As he observed the battle between his subordinates and the ghouls, some knowledge about undead creatures naturally flashed through the great mage's mind.
Without external interference, the souls of natural undead would be completely corroded by negative energy. They would lose their wisdom when they were alive, and become creatures that only had instincts left. Therefore, they should be driven by their instincts to gather in the area with the densest negative energy. Moreover, in this process, the stronger undead would instinctively expel the weaker undead.
The great mage speculated based on this theory that there should be a large number of ghouls gathered in this town because ghouls were the strongest natural undead creatures.
However, the number of ghouls in front of him was far less than what he had speculated.
Natural undead creatures wouldn't go against their instincts. Then, there was only one explanation for this matter, and that was that the Wizard Tower was still exerting some kind of influence on the town.
This speculation made the great mage feel a little uneasy.