The way Demons think in this show is a lot like LLM Chat AIs like ChatGPT work. They don't really think too much, not in the way humans do, but they excel at producing something that humans approve of. If you don't probe them too much, they look just like humans. But if you probe too far you see that their behavior is a facade and that their underlying thoughts are not like humans, and they don't necessarily even understand the words they use to appease humans. What happens when their facade improves? If a demon spent its entire life perfectly acting as a nice and thoughtful human, never causing any harm, would you still call it a monster?
Demons and LLM Chat AIs differ in what their underlying thoughts are. LLM Chat AIs generally want approval. On the other hand, Demons want to survive and eat humans. They use language to manipulate humans and get what they want.