Interesting comparison. We read and watch the HP movies, and we think how foreign it is that there would be a cult like the deatheaters who demand obedience at the point of a sword.
But the Muslim faith is that cult, and they kill their children (mostly girls, because they are sexist pigs) as a matter of faith and practice, for not living their lives as servants to their male cult masters.
The DeathEaters were a secret society of “normal” magic folk working for Voldemort.