Dominance!
That was the factor contested for ever since the Mother Parasite came into being. As the source of the Frenzy Parasites and the first Ancestor to have become in the Parasite Path, Rhachis Ancestor Parasite had control over every Frenzy Beast.
After all, the Frenzy Parasites the Frenzy Beasts relied on to grow stronger stemmed from it. And if it so desired, it could make any Frenzy Beast lose control with a thought. Only the Frenzy Beast Ancestors were exempt from this since they had already fused with their respective Frenzy Parasites and had gained complete control over it.
And similarly, humanity wasn't free from this influence too. They had a secret method to create a layer of protection on their Wisdom Parasites, keeping them free from Rhachis Ancestor Parasite's influence.
Though, once they lose control or their bodies soak up a tremendous quantity of Essence of Frenzy, their Wisdom Parasite would turn into a Frenzy Parasite. After that, they would be under Rhachis Ancestor Parasite's control.
Consider the Child of Wisdom for example. Leaving aside the impossibility of future breakthroughs, just the fact that they have the abilities of both a Warrior and as Esper makes them potential powerhouses. Even though they wouldn't be as strong as either Warriors or Espers of their respective Tiers, this was only true until Tier 5.
After all, their Sync Rate of 100 would be split up between their brain and spine. But, once they reach Tier 6, the percentage of the fused region in both the brain and spine would reach 100 percent, allowing them full control of both the Warrior and Esper abilities—as evidenced by the Tier 6 Frenzy Beast, Colossal Bawling Sheep, Rhachis Ancestor Parasite's mount. It was a Child of Frenzy.
They would become many times stronger than the current generation of Ancestors. Such was their potential. Unfortunately, all Children of Wisdom lacked that shielding on their Wisdom Parasites, causing them to mutate into a Frenzy Parasite with a year.
Once this happened, they were under the control of Rhachis Ancestor Parasite, their life and death decided by it. This was the reason every Frenzy Beast race obeyed Rhachis Ancestor Parasite. Its single thought would decide if their race would achieve greater strength or annihilation.
This was another reason humanity researched heavily in the Mind, Soul, and Aura Paths. It was in an effort to reach its peak first and create a power system that was no longer dependant on the Parasites.
And now, the Skeps had attained that. The Skep Primogenitor had been the first generation of Frenzy Beasts, created when Rhachis Ancestor Parasite was only at Tier 1. And, by breaking through the Tiers and gaining power swiftly on par with Mother Parasite, it upgraded its intelligence, soon realising the concept at play when it was at the peak of Tier 5.
It then tried numerous means, eventually breaking free from the Parasite Path by ripping out its Frenzy Parasite and managing to barely survive. Once Rhachis Ancestor Parasite reached Tier 6, it went in hiding, realising fully well that its decision was correct.
The Skep Primogenitor then spent decades developing itself, using the Skills it gained while being a Frenzy Beast to finally create a path where it could grow by absorbing the genetic material of other creatures.
It was hard at first, since the genetic materials destroyed its body, causing more harm than good. But over time, it figured out a way to refine its body, absorbing the beneficial genetic materials while shedding out the rest.
Eventually, it reached the peak of Tier 5 in strength, the level most Skeps were at today. At this point, it had accumulated enough genetic material to birth an offspring. By sacrificing half of its core, it birthed another Skep.
From that point onwards, whenever they reached a certain level of accumulation, they split half of their accumulations to birth new Skeps. And over the centuries, their population increased. They also obtained the means to create plants that grew on the ocean floor, absorbing the nutrients within.
And, this created a life cycle to bolster aquatic life even further. And once the Skeps gained the ability to birth the Swarm, they made use of these aquatic plants, eventually conquering the ocean. At present, except for some minor corners under the ocean's tectonic plates, everywhere else was occupied by the Swarm.
The ocean was now dominated by the Skeps. And, using the Ocean's depth to its advantage, by layering numerous abilities it possessed, the Skep Primogenitor lived in hiding, suppressing itself as it continued to grow in strength.
It knew very well for a fact that facing Rhachis Ancestor Parasite was impossible. After all, the opponent was too strong and was still growing in strength with the development of the Parasite Path.
That was its advantage of having dominance over a Path. As the Path developed, the ruler also grew in strength. After all, by the notion of a Path's development, it meant the very Earth itself getting accustomed to it, allowing the progression of the Path naturally.
After all, with the arrival of the Parasite Path, three offshoot Paths had been created. First was the Mind Path. The result of its development in the world was the Mental Realm. The second was the Aura Path. The Earth's presence itself was changing with the passing of every day, causing numerous beneficial changes in the creatures living on it.
It was still unknown as to what changes the offshoot of Soul Path would bring to Earth, but it would definitely enrich the Parasite Path even more. And, if that happened, Rhachis Ancestor Parasite would be unstoppable.
The only way to combat that was to attain the peak of their Evolution Path and gain dominance over it. This way, Earth would recognise it and assimilate the Evolution Path into itself, developing it naturally, creating more benefits for the Skeps.
And, to achieve that, the Skep Primogenitor knew that it wasn't suitable. After all, despite breaking free of the Parasite Path, it still had some traces of the influence in its body. And, Rhachis Ancestor Parasite was still able to influence it, even though the influence was negligible to its current power.
So, it meant that it couldn't become the ruler of the Evolution Path. And, the only other Skep to do that had yet to be born. Finally, through some mysterious means that even it wasn't able to understand, the Skep Primogenitor witnessed the birth of a new Skep.
And, a glance was enough to determine that the newborn Skep was capable of becoming the ruler of the Evolution Path and cause Earth to develop the Path even further.
Staring at Rhachis Ancestor Parasite, the Skep Primogenitor spoke, "There's no way I'll allow you to shatter our hope. Your days are numbered, Frenzy."