Well, mine and Space Drake’s, at least. It started with me hammering in a bunch of things, but while I was in the messy brainstorming method of working this theory into words, Space Drake was fabulous in helping me finally solidify these thoughts into a single, coherent thought.

I will go ahead and block everything behind a cut. I’m turning off all of my crossposting on this as well, as I don’t want people who are not wanting spoilers to run across this information. This is pretty crazy and involved and I can’t exactly convey it in a handful of tweets or DM’s on twitter because of the 140 character limit.

I will be giving kudos to both Yui and Bubble for they have also helped me come up with parts of this theory. So this, in no way, is just a single person’s effort.

Also, I’ve learned that this theory opens way more cans of worms that I can’t fully answer.

Emblem
The primary piece of this answer will have been in front of you. In fact, I’ll use an image to illustrate this fact. It’s the image of Kevin from the character book, but it’s not Kevin you want to look at in it. (I don’t have an image otherwise.) – http://pics.livejournal.com/togabitoion/pic/001dzgt2

Zemurian History
Now, history has been told for quite a bit of things. The Septian Church was formed around 500 SE. This is 700 years before Trails in the Sky/Sora no Kiseki. There is the secret organization within the Septian Church- the Grals Ritter. If Anne/Ein’s words are right, then they were formed 1000 years ago. This identifies the birth of the Grals Ritter as being around 300 SE. There is a discrepancy with timing, I believe, on these two, and I don’t think it’s just a matter of rounding numbers.

The Play
Zero no Kiseki had the play, Golden Sun, Silver Moon. This is the story of the ‘Kingdom of Ra’ and a dancer who becomes the Princess of the Sun in order to gain the will of the goddess of the heavens. (They actually used ten here, not sora) The goddess, on a whim, decided to make a game out of it. The influential power in Ra was divided into two clans- the Clan of the Sun and the Clan of the Night. And as the Clan of the Sun’s dancer was to be selected at the Shrine of the Stars, the Princess of the Moon was also named by the Clan of the Night. These two clans were rivals- and, while it was unspoken by the play, the people of the Shrine of the Stars, seemed to act as mediators for the two.

The important part of this play, though, is not the narrated parts. After the scene when Lloyd and Elie barged in on Ernest stabbing Mayor MacDowell in the back, and the chase and arrest… it cuts back to Elie watching the end of the play with her grandfather. The last scene wasn’t narrated, but you don’t need the narration. It’s completely unnecessary. The dance that was originally a battle between Ilya and Rixia (playing the Princesses of the Sun and Moon), became a celebration. If you watch this celebration, it’s the people who headed the Shrine of the Stars, and the Clan of the Moon celebrating on the chandelier…

…while the Clan of the Sun was left behind on the stage.

This is important and the basis of my theory.

Okay.

Now. I’m jumping gears slightly.

The Shrine of the Stars
The Tower of Stargaze, on its lower levels, has a massive pair of scales. Now, there is another place where a pair of scales have shown up in the series. This is on the emblem of the Grals Ritter. I’d offer it, but I can’t, because I don’t have a scan on hand. This makes me sad, but I trust you can look it up. If you can’t, remind me with a mention on twitter or a comment and I’ll try to scan it from one of my artbooks.

The Grals Ritter are pretty much devoted to their old ways. They have a lot of technology people don’t have (look at the Merkabah), and a lot of power in subtle and ‘under the radar’ ways… but they still have a lot of things they don’t bend and waver on.

I think the Grals Ritter are the people that were represented by the dancers of the Shrine of the Stars in the play. They were not part of the current ‘Septian Church’ from the beginning, and they do remember their heritage and legacy. They have no reason to lose it, forget it, or stray from it. Another piece of my evidence is the first line of Kevin’s Grail Sphere move in SC and 3rd: I hold in my right hand, the Grail of the Stars.

But then…

The Clan of the Night
If the Grals Ritter are the original people who occupied the Shrine of the Stars, then who is the rest of the church? They’re the Clan of the Night, of course. Look at the play. They, too were celebrating. This means that they, and the Grals Ritter, got away with both princesses. Both goddesses? Maybe. Something like that, I think.

Now, I don’t know why the union happened. Maybe there was something mutual that the stars (I’ll just call them that for now- I don’t know a ‘clan’ name for them) got out of this with the Clan of the Night. Or maybe the Stars manipulated them into it. I can’t say for sure (but with the grail- see Kevin’s line above again- being the prominent part of the Septian Church’s emblem, I want to think maybe so).

But it’s just fact that the Septian Church is the union of the Clan of the Night and the Stars.

The Ancient Battlefield
I think this happened after the whole union between the stars and night. Some sort of retaliation occurred from the Fortress of the Sun. Because this union not only changes the balance of things, but it also takes both ‘princesses’ (using terminology from the play) away. Maybe the two of them became the goddess. Or maybe there were two goddesses. I also imagine that perhaps it’s likely that the Clan of the Sun did something that even the Stars found reprehensible. As such, with the Night, they both attacked the Fortress of the Sun and ravaged it.

I also believe that something happened to the daughters/princesses during this. Harmed, killed… separated? Buried?

The Clan of the Sun
The Clan of the Sun is, with all this forward, pure and simple: D.G. They were left behind for some reason, and as they no longer have their goddess, they have turned to another source of power? Or maybe they fell into temptation before hand. (This is part of what I meant with the more questions thing before.) However, the next part explains a lot more about this.

Who is Eidos?
A lie. Plain and simple. Eidos is a way to control the public. She is not the goddess of the original clans. She is the ‘Sun’. Maybe it was meant to make people think of that era believe that the Clan of the Sun was involved, (If “Ra” was as powerful as the play implies) a way to completely discredit the Clan of the Sun, or something else. What I do believe, however, is that D.G’s bold statement that Eidos is a lie is fact in this theory.

However, by doing this, and with D.G waving about at the Septian Church, the Church can turn around and decree that D.G has forsaken Eidos. While the Clans of the Night and Stars agreed to ostracize the Sun… now the entire continent will as well.

But Aren’t You Forgetting About Someone?
The Ouroboros? No. No, I’m not. You see, after several hundred years, it’s easy for a group to become disillusioned with a union it was, most likely, forced into. I think the Ouroboros- or most of it, at least- may be chunks of the people from the Septian Church that belonged to the Clan of the Night. They dislike the Grals Ritter and their methods for some reason, or with the Grals Ritter’s influence, they’re unable to take actions that they felt were necessary.

I think one of the princesses still lives on as the Leader of the Ouroboros. She may be of the Sun or the Moon. Not sure which, really.

The Other ‘Princess’?
Is KeA. And I think that, by awakening KeA, this is going to bring down all sorts of people onto Crossbell- some having been vying for control of Zemuria, but having been unable to do so with the Septian Church, D.G wanting one of the princesses back, the Ouroboros with the Leader wanting to save her sister… KeA’s statement of ‘Find me’ is important, but nowhere near as important as it is until this theory is put into place.

I might type in on this more as I figure things out, but holy crap, I’m already at 1500+ words on my word count and I’m running in circles mentally. D:

Feel free to add your opinion in comments. I’ll be happy (and hopefully quick) to respond, and continue to discuss this theory.

EDIT: Varion has posted a log of my rant of this theory on IRC. You might find it more coherent. Maybe.