This episode has a cool concept, but the pacing feels really off to me and some parts of the story feel messy, out of place or poorly explained. I actually feel like this episode would benefit from more exposition earlier on in the story to lay some of the groundwork so that it's not so suprising when things occur later in the episode and only then explained (which ends up making a lot of events feel very convenient, like they're happening only for the sake of the plot, when, in reality, they do actually fit into a (mostly - I think there are a few plot holes) consistent set of lore). On the positive side, this episode does bring us an absolutely lovely original song.