I don't like fantasy manga where dragons are counted among the demons. It's still okay if some random humans call them demons, not knowing any better, but if they count themselves as demons as well, then it's canon and I don't like it. But of course this is nothing but my personal opinion, and might not make any sense in Japan, where what is commonly translated as demons into English aren't necessarily demons, strictly speaking, as we know demons in Western lore. That being said, plenty of manga do keep them separate, so it's not like the Japanese wouldn't understand my point.