He was in high spirits, almost humming a tune.
Had the experimental subject attacked the crowds in broad daylight, it would certainly have brought them considerable trouble. Fortunately, not only did the experimental subject's brain retain the necessary rationality after being toyed with repeatedly by the scholars from the bio-research institute, but it had also managed to develop a reasonable hunting method through a series of hunts. Very cooperatively, the subject appeared in the night.
The hunts of the Seven Sins were always conducted at night.
It was neither habit nor tradition. Simply put—whether it was the hunters or the hunted, both had reasons to avoid public scrutiny. Sunlight would only expose unpleasantries that no one would enjoy, hence neither side needed sunlight.
Tars Village was the hunting ground, their prey the alien form that roamed atop the walls.