Demons are not just pagan, although pagans may have recognized them as well. The time of year is a pagan thing and whatever that nonsense is about the veil. Demons are real and common to both religions.
No one has mentioned All Souls’ Day. All Saints’ Day is a wonderful day—just the idea that many people have achieved sainthood, not only the ones in the Church calendar and history but many people we had never heard of and never would hear of, and possibly no one at all knew that they were saints.
But the idea of all those people who had not achieved sainthood? That was a mindblower for me when I was a kid. Not that I knew the word mindblower. Freaked me out just thinking about them on November 2. There was a day devoted to them. Far out. Although they were not considered worthy of a Holy Day of Obligation.