The more I think about their mythology of the UW, the more I think they are actually modeling a lot of it on the Buddhist concept of bardo where the person’s experience after death and before the next rebirth is often negative, and is the fruition of one’s karma (past actions). The Western interpretation of this concept, which is I think what they’re going with, is that “hell” is really the process of battling one own’s “demons”
I think that fits for the most part. I think there are some weird inconsistencies that have more to do with lack of shading of very minor side characters than anything religious or karmic. For example, Auntie Em and the Blind Witch don’t seem particularly bothered by their status as trapped. In fact, the Blind Witch seems perfectly content as did Auntie Em until the heroes arrived and mentioned Dorothy. The Blind Witch is such a minor character and is being used more for Underworld!Google and Comic Relief that the show missed a big opportunity to have her be haunted by her former suppers.
They also missed the mark, then, with Hook–a known murderer who kept trinkets from his victims and who most recently killed Merlin. Since Hook is technically still dead he should be battling some pretty hefty demons….and yet…