Can you speak to the trend of monastics who are so vehemently against fantasy literature and tell laity they are opening their children up to demonic possession?
St. Basil the great teaches us to be like the bee and take the best from what we find in secular literature (and culture). In my opinion, there is fiction that is God-pleasing, because it presents us with certain virtues which are noble and worthy of emulation. There is fiction which is pure fantasy, but is nevertheless relatively neutral or benign: children must be allowed to use their imagination, since it is necessary for certain aspects of our life here on earth. The overindulgence of fantasy, however, is not helpful in the spiritual life, because the reality of God surpasses the mind. And then there is that fantasy which is not from God, seeks to possess our minds, and leads us away from Christ.
For more detail, see my Notes for Homily 53 in Palamas: Saint Gregory Palamas: The Homilies (2022 rev. ed.).