One Question That Needs Clearing Up...

[Masamune·1600]

You can't have Dream Zanarkand or Sin if there is no fayth to begin with.

Actually, no. Sin's existence is completely independent of the Fayth.

But if Sin is just an Armour, it doesnt need Fayth to exist. So why couldnt Yu Yevon become Sin, obliterate Zanarkand and once the survivers become the fayth couldnt Yevon begin summoning the Dream Zanarkand from within Sin

With the exception of the question of chronology, this is what happened. Dream Zanarkand is manifested by the Dreaming of the Fayth; Sin, however, exists as an autonomous entity.

Having said that, however, this turn of events forces one to assume that, among other things, Yu Yevon could begin the Summoning once Sin had already been formed.

Now can the Fayth freely travel between Dream Zanarkand and Spira, without Sin's help? Bahamut's Fayth seems to be able to appear there at will, albeit in a noncoporeal form.

The Fayth appear in Dream Zanarkand only in a disembodied spiritual form; this, however, would be the same as projecting an appearance anywhere else on Spira. As Dream Zanarkand is an actual physical location, such an appearance is, in and of itself, nothing profound. However, one would suspect that there are certain limitations involved in interposing in one's own realized memory, as the Fayth might have otherwise found a mechanism to end the Dreaming independent of the original accident (Jecht's contact with Sin).

The self-contained nature of Zanarkand made me wonder how the Abes could be playing another team, but when I replayed the opening I found out the Abes were playing the Duggles from block C-south. I guess Zanarkand like is New York City, with multiple teams for the same sport.

Yes. In fact, this is inevitable, as Dream Zanarkand is self-contained, and is unaware of anything beyond th boundaries of itself. As a result, it is completely self-depenedent--any form of entertainment would have to come from within.

Why dun we look at it this way. If this can be done, then there isn't any point of creating Dream Zanarkand cause Yu Yevon can just create Sin and destroy the Bevelle guys so the Real Zanarkand will be safe...

This is incorrect, as Sin is innately destructive. There is no check upon Sin as regards the preservation of the original Zanarkand (indeed, Sin is the destroyer of the city); therefore, this avenue of thought is impossible. Understandably, you're arguing from another point, but the opposing view does not require this either.

Well yeah, there is that argument. But whose to say that he will be able to control Sin once Bevelle was destroyed and prevent it from destorying Zanarkand as well. This way, he can preserve Zanarkand with even more control than before and can still destroy bevelle should Sin happen to be passing. By destroying Zanarkand as Sin, his given the survivors a reason to become the Fayth, to preserve in a dream what was lost in reality

In order for this continuity to work, one would have to assume the following.

1. That Yu Yevon could begin and continue to Summon Dream Zanarkand after giving himself to the destructive reality of Sin

2. That the residents of Zanarkand, without the urging or input of Yu Yevon, would have independently decided to end their lives as humans and become Fayth

3. That the Fayth would have wanted to dedicate themselves, without the input of influence of Yu Yevon, to the perpetuation of a substantiated memory of Zanarkand

4. That the Fayth would have believed that Yu Yevon both could begin Summoning having become Sin, and would have locked himself into the Summoning of Dream Zanarkand

5. That this sequence of events would somehow take place more effectively than the established chronology

Again, your idea is not terribly off, but the sequence of events you propose does not fully work.

And as far as I know it, he had control of Sin since Sin never attacked Dream Zanarkand until Jecht become the final Aeon and wasn't quite under his full control at that moment.

Incorrect. Yu Yevon's control over Sin has never been more than marginal; if it were more profound, Yu Yevon could have simply used Sin to defeat Bevelle, and allow the original Zanarkand to persist as a living city. Moreover, the original event which threatened the "spiral of death" was actually Jecht coming into contact with Sin. As the "system" embodied by Sin could only be threatened by interrupting the isolation of Dream Zanarkand, Yu Yevon would not have desired this contact on any rational level.

Further still, Jecht had nothing to do with the attack on a personal level; Sin is inherently destructive, the center of the "spiral of death," and so brings destruction wherever it goes. Jecht was responsible for Sin going to Dream Zanarkand (and in this way, he influenced it uniquely, although one must remember that his initial contact with Sin was accidental), but Sin attacked Dream Zanarkand because it is Sin, not because the system of control was any different than it had been throughout the past ~1000 years.

Also, if I am not wrong as I stated in the previous post quoted from the script, the Final Aeon act as a "core" while Sin as the "shell" to enable the whole thing to happen. So, in order to have Sin, you must have the core.

In a sense. Yu Yevon himself was the original physical foundation for Sin; the possession of the Final Aeon for such a purpose only came about after the original Final Summoning pierced Sin.

I was refering to the real zanarkand, and this does imply a certain level of control that Yevon has over Sin, even with the influence of the final aeon, only in this case, Jechts influence was greater

Not really. Refer to my comments above. In the case of Braska's Final Aeon, it would seem that Yu Yevon had not fully taken control. This process was gradual.

Jecht: I can't hear the Hymn so well anymore. Pretty soon, I'm gonna be
Sin. Completely. I'm glad you're here now. One thing, though... When it
starts, I won't be myself anymore. I won't be able to hold myself back.
I'm sorry.

At no time can one truly overcome the destructive nature of Sin (with Jecht/Braska's Final Aeon as the core, it could temporarily be pacified by the Hymn of the Fayth, but this is temporary). However, Jecht obviously had limited directive, which in time would have likely disappeared completely.

But wasnt Yu Yevon the Original Core, before Zaon (Yunalesca's Final Aeon) defeated Sin and whatever was left of Yevon possessed him? there was no final aeon at Sins birth

Yu Yevon was the original foundation, the anchoring point for the formation of Sin. Yu Yevon's physical body would have been destroyed during the first Final Summoning; however, his "soul" could from there possess the Final Aeon, and perpetuate the spiral of death.