Regan's Perspective
Unlike William,
ever since Regan had stood before Black Roundworm Company's headquarters, his not-yet-ascended mechanical body had continuously generated unease. It had even autonomously generated powerful electric currents to stop him from entering the building.
That was because the body's systems had detected an existence inside the building capable of completely destroying everything Regan had forged so far, bringing the so-called "Mechanical Ascension" to an end.
When he took the elevator to the top floor of the headquarters and saw Boss's true form, he finally confirmed the source of that unease.
While working alongside those old fellows who loved conducting research, Regan had used his free time to read some important information they had recorded about the Ancient Times,
including mentions of the "special groups" second only to the Plague Lords in each Source Plague Zone.
The Seven Marquis of Crimson Manor, the High Table of the Cancer Palace, and so on. They represented the leading existences of the Silver Circle and jointly managed the armies under the Plague Lords.
As the former Parasitic Main Nest, it naturally had such a group as well. They were known as the "Protozoon of Hallownest."
Unlike the Seven Marquis, the Protozoon of Hallownest consisted of only three members, each of them incomparably powerful.
This strength did not refer solely to the parasitic protozoa themselves. The "hosts" infected by those protozoa had likewise reached the level of the Silver Circle's leading existences. Such host vessels were often called "Hallownests," signifying the most sacred and highest-grade containers.
When such a host combined with a parasitic protozoon, it would reveal an incomparably powerful form. During the Ancient Times, any Sick One would show reverence whenever they spoke of the Protozoon of Hallownest.
Precisely because of that strength, when war came, the outsiders noticed this