MLP's Dubious but Intriguing Spirit Lore

My Little Pony: Friendship is Magic has lovable characters, interesting settings, and quite a few captivating stories, but there are some aspects of the show that most fans would agree haven’t been fleshed out nearly enough. Aside from the lack of insight into some important characters such as Princess Celestia and, until relatively recently, Spike, there are many aspects of the show’s lore that have been unfortunately neglected. Take, for example, the enigma of spirits in MLP.
Other cartoons aimed at a young demographic, such as Avatar: The Last Airbender, and even those aimed at a junior sort of demographic, such as Sofia the First, are not ashamed to admit that they have some sort of spirit world or spirit realm as a part of their respective fictional universes. In addition, the Harry Potter books and movies, from which MLP has garnered much creative inspiration, particularly in the earlier seasons, frequently feature a variety of spirits such as ghosts and boggarts. MLP, however, has been rather hesitant to paint a coherent picture of its spirit world.
In the episode “Bridle Gossip,” Twilight Sparkle tells Spike that spirits and ghosts are make believe entities. In “Hearth’s Warming Eve,” however, we are introduced to the windigos. In Native American mythology, windigos were evil spirits of the forest that would possess humans and transform them into cannibalistic monsters. Obviously, because cannibalism would never have gotten past the censors, much less in a Christmas special, the windigos were reduced to spirits that fed on and strengthened malice among ponies. Nevertheless, this does contradict Twilight’s statement about spirits being make-believe.
Another instance in which spirits appear in MLP is in “Do Princesses Dream of Magic Sheep.” In this episode, we are introduced to the tantabus, which is a lot like a tulpa from Tibetan folklore, as both are entities or “thought-forms” that spring forth from the consciousness of their creators. Nightmare Moon could also be considered a tulpa, but she would be of the variety that does not become totally independent of its creator, instead taking over his or her consciousness in a Dr. Jekyll and Mr. Hyde manner. The tantabus, however, is much more clearly presented as a spiritual entity created by Princess Luna.
In the Season 7 finale “Shadow Play,” we are introduced to the Pony of Shadows, who used to be a unicorn named Stygian. It is revealed that Stygian, after being cast out and forsaken by his closest friends, discovered a sort of underground lair where he became possessed by an evil spirit that used his grief and anger in an attempt to extinguish all light and hope from Equestia. This could easily be seen as the first actual instance of demonic possession in MLP, as this was cut out of the windigo lore, and even though Luna was shown to worry about turning into Nightmare Moon again, this was most likely because she was worried about the entity growing from within her. Contrast this with Stygian, who needed to seek out the Pony of Shadow’s lair in order to be possessed by him. Most likely, this difference has to do with the fact that Stygian did not have advanced, powerful magic as did Luna, and was therefore unable to create such a dark entity.
In conclusion, MLP has often pretended that spirits are non-existent in its universe, when this does not really make sense with many known aspects of it, as spirits are shown in multiple instances to exist. What could be a solution to this problem? Perhaps there isn’t a fully satisfactory solution. A random and rushed introduction of a variety of spiritual elements, such as ghosts, is unlikely to be very effective this far into the series. A better option, quite likely, would be to expound on the lore of already-introduced spirits, particularly the windigos and the Pony of Shadows.