"My guess is that it is not that the humans can't take that region but they have no need to. The demons within this territory can't even hope for some backup to resist the neighboring territories. Meanwhile, these neighboring territories have colluded with each other. They send their men within the Territory, hunt Demons or beasts, and sell them to an organization in the black market. After all, an ice-type beast's organs, beast core, and an Ice Demons' core and organs are bound to be precious." This caused Helena to grit her teeth in anger.
She was a Demon Lord. To know that the Humans were selling the organs and cores of her brethren, she couldn't help but want to kill them.
Saito said to her, "You will go there. You are going to unite the demons within that place. There shouldn't be a demon as strong as a demon lord so nobody will be your match. Just make them submit to your power. However, do make sure to try this in an inner area."
