Board Thread:Wiki-Related Discussion/@comment-5279400-20180106162350/@comment-25926288-20180107000052

There are realms of dark magic, yes. However, there is a realm called the Dark Realm.

That would be like changing Wonderland to Wonderlands. Two different concepts. There are many realms of dark magic, but only one is called the Dark Realm (which we see that the Dark Fairy rule over).