Interesting.
As a Protestant, I was warned away from many things. Anything at all that had anything to do with spells, demons, witchcraft, even as a fantasy, would fall in here. (And as a result, I felt guilty for playing Final Fantasy games, because they usually involved "summoning" a powerful creature to help, and some of these were named for pagan deities.) But it can go so far as to prohibit not only Santa Clause on the charge that he takes the focus off Christ, but the celebration of Christmas/Nativity itself "because it's not in the Bible" or because it's "pagan".
There's a continuum, and it goes pretty deeply into prohibiting EVERYTHING, including any dancing, birthdays, alcohol, holidays, television, music, and so on ... and some of these ARE explicitly mentioned even in Scripture.
But what's ironic is that most would consider the Narnia series, or even the LOTR series, to be "Christian" in a sense, because of themes, even though they explicitly include witches, spells, practice of magic, evil lords, etc.
Funny thing, now that I'm thinking of it. I used to love reading novels written by Stephen King, then Dean Koontz, and then I got into other writers in the genre. (I was not practicing as a Christian at that time.) But after a few years, I noticed that it had created some kind of darkness within me, and affected how I viewed the world. As a result, I put those down myself. (And btw, it may very well just be me, it might not do the same to someone else).
I love that Orthodoxy tends to be practical.
Does it obsess and take time away from God or responsibilities? Then you probably shouldn't be doing it. (Whatever "it" is.)
And with my experience of the dark novels, I would add: Does it affect your soul, your outlook, bring darkness to you? If it does, then of course don't do it.
The only danger being the possibility of not recognizing this. But even as much as I was disconnected from God, through His grace, I still eventually recognized the fact that the books were doing that to me. And now, I am often made aware of that influence immediately, while I'm watching a movie or whatever - and I simply turn it off. I can't say how easy or difficult it might be to recognize the influence, and I'm in no position to say for anyone else. Just another factor one might need to consider. If I had any doubt, I would certainly ask my priest or my geronda.
But I'm starting to thing that the black and white lines drawn by many Protestant ministers (in what I do believe is a sincere attempt to put up fences in order to keep their flocks safe) - can be a bit arbitrary and not necessarily where the lines really ought to be.
For what all that is worth.