Ok, here is a synopsis of the ending for everyone who dosen't get it. Tidus IS a dream of the fayth. The fayth are the spirits of those who were killed by Sin in Zanarkind during the war with Bevelle 1000 years ago. As fayth, they began dreaming of the old Zanarkind as the way it was, to keep themselves happy while being tortured by Sin and by the guy who controls him, Yu Yevon. Remember, Yu Yevon was fighting against Zanarkind way back when, and the hymn of the fayth was to protest his tyranny. Anyways, that's the deal with the fayths and thats how Tidus was created.
Now on to the deal with the butchering of your Aeons. I found this to be a real clever plot twist for the end of the game and I liked it alot. It's the final way for the programmers to screw you over at the end. Throughout the entire game you are constantly trying to make your Aeons as powerful as possible, and when the ending comes, they're just that more difficult to defeat. It's genious really. Anyways, you have to kill your Aeons because they are the only way that Yu Yevon can create Sin. Therefore, that final link must be destroyed so Sin can never be created again. When you beat Yu Yevon, you see that all the statues that contain the Aeons lose their power. Thats because the fayth can finally stop dreaming, and their dreaming is what kept the Aeons alive. Just like Tidus. The fayth dreampt to give hope to the people of Spira until someone like Tidus came along.
Now on to the question about why the fayth "died" at the end. Well they didn't die, they were already dead. As I stated before, they were dreaming to keep hope in Spira. Once Yu Yevon was defeated, they were no longer needed because: Sin is gone forever, and the religion of Yevon is now obsolite. They just got up and left. Besides, they said they were sick of dreaming, and now they can finally rest in the farplane, or whatever.
Now, replying to the questions posed by some people about how a dream and dead people can exist in Spira, I have a little theory. This also ties into the questions about Tidus in the ocean. One question you have to ask yourself is, "How in the world did Jecht get into Spira and out of the fayth's dream to help Auron and Braska?" Because if Tidus was a dream, obviously Jecht must be one too correct? And why would Sin absorb Jecht, like Jecht did to Tidus? He wouldn't. And then you have to ask yourself, "How can spirits and Aeons and fayths etc... also be phisically present in Spira?" Obviously, if Spira was real, they couldn't. So this brings us to the conclusion that Spira isn't real. It's just as real as Tidus; Spira either has some kind of "Matrix" thing going on, or it's just part of another big dream. When we see Tidus waking up in the ocean, it's him starting a brand new reality, or becoming a brand new dream. You see him curled up in the fetal position which gives me the impression that he's being reborn. It's in a sense, a tree branching out, creating more and more realities as it goes on. Each one completely different, kinda like each version of FF <img src="/images/graemlins/wink.gif" alt="" />
But that's my take on the whole thing and just to let everyone know that yes, I do have a life and no I'm not a complete geek, I just beat the game last day and this topic is still fresh on my mind. Now that I'm done, I think I'm going to have a beer and have sex with my girlfriend, because writing a post this long on a video game has made me a little uneasy. So chew on what I've said and think about it. Ladies and gentlemen, I bid you adieu.