After monsters killed humans, they received a certain boost. Uh, not by Devouring souls, but by Devouring Negative Aura. When people died, large amounts of Negative Aura definitely emerged—despair, resentment, hatred, and so on.
As for souls, according to the agreement between Compound V Big Tree Scar and Chthon, he took fifty percent exclusively, while the remaining fifty percent was divided among Chthon, Lord of Chaos, and the others.
To be honest, neither side was very satisfied with this split. From Scar's perspective, the main force was the Negative Legion I sent out, and I only got fifty percent?
From Chthon and the others' perspective, we were holding back the Mechanical Demon King for you and handling all sorts of matters. There were so many of us, yet we only got fifty percent?
Although neither side was satisfied, everyone saw the bigger picture. Thus, both sides reached a partnership and harvested human souls together.
The one in charge of the Negative Legion in Berlin was the First Commander, Bone Demon. The one in charge of Paris was the Second Commander, Blade Demon. He was not humanoid, but simply a blade—a super-sized saber ten meters long that seemed overflowing with Killing Intent.
Blade Demon gave the same order as Bone Demon. He and his personal guard would protect the Guardian of the Altar, while the other monsters went out to slaughter humans.
The Altar was the most important thing. As long as it remained, the Negative Legion could continuously teleport to Earth. Therefore, although Blade Demon wanted to kill humans personally, he restrained himself.
The one in Miami was the Third Commander, Wind Demon. On the surface, he looked like a human wearing a trench coat, but his true form was a mass of wind, somewhat similar to Wind Demon, Andrew's