The Island is Pandora's Box and Kate is MIB's loophole by Maori8

After watching the Richard-centric episode, I came up with this theory of how the show is going to unfold.

First, I think the Island is the only place on Earth where God, the Devil, and humans are allowed to co-exist. We have three sides
Jacob, Paradise, God etc.... the good side
MIB, Hell, Devil, etc... the bad side
and finally the human beings.

The island is the only way to link humans on Earth to Paradise and Hell.
When Richard says that the island is Hell, he's not entirely wrong, the island is a combination of both, Hell and Paradise, that's why it can exist on Earth, and all of the members of the three sides can go to the island, That can explain what Isabella meant to Richard when she said "We are already together", is because both alive and dead people can co-exist on this island (It is not exactly Purgatory because alive people can go in) .

But now that Jacob's dead, we can only assume that the island is becoming Hell, that's why MIB threw the white stone out of the balance... because the balance is not stable anymore. Like Jacob said " the island is the only thing keeping the evil from spreading" It means that, if MIB leaves the island, "We are all going to Hell", every living person.

Like MIB said, Jacob took his humanity away from him, So the only way that Jacob can be killed is by a man, that's why MIB can't kill Jacob, but everyone he manipulates into killing him can (like Richard, Ben, etc...). and that's why he can't be killed either, because he's not human anymore.

The metaphore used by Jacob reminds me of Pandora's Box: There's a box that let spread all the bads of humans, but Pandora closed the bow just in time to keep one bad in: Hope (or the better translation would be "the wait of bads to come". If you want to check wikipedia you'll understand what I mean)
When MIB breaks the bottle at the end of 6x09, we, the audience, are showned that the darkness will spread, and that it has already spread in all the Pandora's Box, that means the island ( that's why people are being claimed, like Sayid). If MIB gets off the Island, all the darkness will spread in the entire world.

So, someone is going to stop MIB from leaving the island, otherwise the flashsideways wouldn't exist (because the island doesn't exist anymore, yet all the characters are still human, and the world is still a balance between good and evil on the flash sideways), and I think that someone is going to be Kate for many reasons
- Pandora was a woman
- Kate is not one of the 6 remaining candidates that Ilana is supposed to protect (this are: Sayid, Jack, Hurley, Sawyer, Jin and Sun, but again, I'm theorising)
- She has been, from season one, the only person to stand between Jack and Locke, and she will be again. (because I think that Jack will be the remaining candidate for Jacob's replacement, and MIB has taken Locke's appearance, So it will be again a Jack versus Locke duel at the end, as well as a Jacob versus Man In Black duel)

So Kate will be MIB's loophole, the flaw in the plan, the same way that Jacob neglected Ben, MIB neglected kate. I think the cave belonged to MIB, and therefore, we saw that Kate's name was already crossed out, whereas in the lighthouse, her name was still there, and we know that the lighthouse is Jacob's: that means that MIB didn't think Kate was important whereas Jacob did. So Kate is like the last resort in Jacob's plan.

To finish with this theory, I think Jack is going to want to stop Locke from leaving the island, but he's going to fail, there will be a war involved (that's when Widmore comes in) and there's going to be a lot of dead people, and at the end, Kate, the only person on the show that seems to care about people's feelings and remain the most human of all (like in 5x16 when she said "since when shooting kids and blowing up hydrogen bombs become ok?") will finally stop MIB from leaving (I don't know how, maybe she will talk to him about his crazy mother, I don't know, but she will succeed) and then something is going to happen to the island, everyone on it will die, the island will be under water and the story will end with the flashsideways story (because if the island doesn't exist, the plane never crashes). Kate will be the only remaining person on the island who will not have chosen sides, and that's why she will be the only one "representing" the third side, humans, and that'! s the side that's going to win.

So here are going to be the charcter's final Destinies, to resume
- Locke and Ben have already had theirs, by being Jacob's loophole
- Ilana will die attempting to protect the remaining candidates until the final one remains
-Miles and Hurley have a gift, and their destiny will consist in using their gift to help other people to fulfill their own destiny (like Hurley did for Richard)
- Richard will help Jack with his knowledge to stop MIb from leaving
- Sun and Jin will die (they are for me the Adam and Eve in the caves) because they will chose different sides in the war that's coming.
- Frank will die refusing to pilot the plane for MIB. That is his destiny.
- Sawyer will die because he will try to leave by himself from the island, that will be his destiny (every man for himself)
-Sayid has been infected, so whatever he does he's destiny will be to be a killer, that's why he's the only one on the flashsideways til now to make the same choice that he did in the real timeline (that means, killing)
- Claire I don't know yet, but I think she will finally at the end side with Kate and help her to stop MIB from leaving the Island.
- Kate is going to be MiB's loophole.
-Jack will be the final candidate and he will become the new Jacob and he will die trying to stop MIB.

The show is going to end with all the people dying on the island but living on the flashsideways... I can't tell you what my theory is about the flashsideways ending, because we don't have too much knowledge yet!

Thanks for reading! and sorry for my english, that's not my first language (nor my second lol