The battle erupted without warning.
The Undead Legion surged with the roar of mountains and seas. Rather than leaping into a chaotic attack, they formed interlocking battle formations of bone.
Although the formation was simple, their movements were still somewhat disorderly, and they probably could not yet act as one at every command, a formation was still a formation. This was the first time human cultivators had seen this other side of the Undead. It also indirectly proved that these things were organized. Their organization might still be primitive, but once established, it would mature sooner or later.
A combined formation of seven thousand Undead-not even humans, let alone these things, could easily bring its full strength to bear.
Battle formations were an exceptionally profound field of study. They required a shared cultivation lineage, a deep understanding of Spellcraft, coordination cultivated through prolonged familiarity, and, above all, strict discipline and the willingness to sacrifice the individual for the whole.
Thus, the difficulty of forming an array for lesser cultivators was directly related to their numbers. The more people, the harder it became. Ideally, one would lay out a formation alone; only then could one command it as easily as an arm commanded its fingers.
The notion that three people in formation could unleash the power of five, ten could withstand an attack by a hundred, a hundred could sweep all before them, and a thousand... was very naïve.
In reality, once too many people were involved, they instead hampered one another. The more there were, the worse things became. Only after cultivators reached Infant Transformation and grasped the conceptual essence of the Great Dao would this fundamentally change.
If even humans were like this, there was still less to be said for Undead, cultivation creatures that relied purely on instinct.