So I’m wondering to elaborate on this theory, what if the wings stand for a chapter each? And here are more wildcards I’m throwing out.

There are six wings, a heart, and a crown on top. Maybe the gate leads to the soul-having Angel? What would the crown even indicate? Having power over all chapters?

I also think the Angel may possibly depend on the route. In side A, it might be the Player; but in side B, it is Noelle. The Player Angel’s desire is to finish all chapters, whereas for Noelle, it is to be free from her set path, and to find Dess.

In Chapter 4, when debugging and showing the Angel prophecy, we see Castle Town. I think it indicates where the Angel proper will first appear. If so, that could indicate the Vessel or Noelle. I find it suspicious that the round area in Castle Town could embrace a fountain. So perhaps a new fountain will be made in there.

A shit idea, but …

Just as Lancer is a card come alive as a Darkner a ‘layer down’ (in the Dark World), so is a Titan a fountain come alive as a NEO-Darkner a layer down. What if Castle Town is a body’s Dark World? I’ve sometimes wondered whether the top is the head, the circle the heart, and the lower area with houses, the ribs. If so, what if all Castle Town is Dess’ body?

Dark Worlds are shaped after a person’s will. Perhaps Ralsei is a Darkner of Dess’ mind, of pure darkness because the source of the Dark world (Dess) is dead, and Asriel was held dear by Dess, which echoes in Ralsei. So maybe Ralsei’s “purpose” is to comfort and guide those who are in darkness.