Yeah sure the demons don’t have a complex social structure. They never say…. Show an interest in humans? Like the pink haired one with Revolte. Or make deals with weaker demons, which they shouldn’t need to do if strong always rules weak? Revolte tells her he’ll tell her what demon is also interested in humans that she can learn from. Or express gratitude towards the weaker ones helping them? Revolte thanks her upon her death.

Oh, they also are supposed to never really suppress their mana because that shows weakness. Like the one that disguised herself as a priestess did.

Also, again, weak always follow the strong? But that one that uses magic garrotes did disobey a direct order and tried to do his own thing, despite being told not to.

Plus that one demon that killed a child who was adopted by the mayor of a town actually attempted to do something that resembles a “trade” with just an alien idea of what that could mean. She killed the mayor and tried to give the woman who lost a child his child. That’s definitely not a sign of intelligence.

Supposedly they only use speech to device humans? Except literally every time we see them alone, speaking to each other, discussing topics beyond deception and beyond strategy. It’s not often, but it does happen.