Exotic Matter, Nemesis and a Volcano by babaganoosh

We've been led to assume that the candidates are there to replace Jacob. However, I believe they really are the candidates to replace MiB. Let me explain what I believe Jacob and the Man in Blacks story really is and how it IS the overall story of LOST:

--ORIGINS OF MIB/JACOB--

Lost loves to throw us in a different direction to make us go "oooh" like with the Others apparently being Good guys, like Ethan not being some alien and just an other, and same with Danielle. Just curve balls. And this will be no different with Jacob and MiB. We think they are some sort of gods or whatnot but what if they are really just two time travelers? We've been shown an excessive amount of the DHARMA Initiative for the most part of the show...for what? MiB and Jacob are most likely 2 members of DHARMA DURING THE TIME THE LOSTIES WERE THERE!!! (or they can be members of the Others, I just think DHARMA sounds cooler) Think about Jughead exploding, there was a flash...because MiB/Jacob turned the wheel at the Orchid during that incident, saving the island and possibly causing the alt (more on the alt later)and thus sent all time travelers to their respective timelines, unbeknownst to young MiB and Jacob of course!

Jacob/MiB landed in the distant past and attempted to find a way to get home. I'm assuming they traveled to a time where the donkey wheel hadn't been placed yet because MiB/Jacob were the ones who placed it. More on that soon.

--THE VOLCANO--

There is a volcano on the island. They've said it in the show during the Ben flashback episode and another clue is that MiB is covered in volcanic ash. I highly bet the volcano will be seen in the last few episodes of the series. What I think happened is this was the first incident of time traveling EVER on the island. Perhaps this opened a new crack into the exotic matter dimension of the island at the volcano or MiB/Jacob found it (just like the energy in the Orchid) after exploring for sometime. They might have gone to investigate and MiB fell in essentially becoming the "cork" because he is now part of the exotic energt and if this energy splits off from the rest of the energy then there are diabolical effects. Simple. Now I think the "smoke" is simply the ash from the volcano where MiB's "soul" or "consciousness" is located and since he is inside the matter and in the real world he is split and "stuck" inside the exotic matter (or if the whole island is the energy then ! he can manifest from anywhere on the island but that wouldn't explain the ash). Simply he is a shiny, white ball covered in ash that is part of the exotic matter of the island but has a mind of its own (his) and he can utilize the properties of the matter like appearing to be a deceased person. When Jacob died MiB lost this ability, because in death Jacob could still control MiB but in the way of stopping him from taking false forms. In all his years of life (yes Jacob is just a man)he couldn't alter what forms the MiB appeared in but he could keep him on the island (we don't know how exactly, just another property of the exotic matter).

--WHAT HAPPENED AFTER?--

But MiB is not the first thing to be placed in the exotic matter. The Donkey Wheel has been as well. Jacob placed it there after seeing what happened to MiB as means to go about his plans. (so the donkey wheel incident becomes a loop in time, a circle, theme of the show etc because since whatever happened, happened, the wheel was always placed there by Jacob). Jacob tells MiB that there has to be a way for them to get MiB out and he vows to stay with MiB until the end of time so that he would never try to leave. Jacob might have then used some of the exotic matter on himself (think something like Desmond, he might have dipped his hand in it or fallen just like MiB did but he didn't fall in the volcanic part therefore giving him a different look) thus giving him the powers we know him to have (touching someone simply passes on a little bit of the islands power therefore that person cannot die because they have a piece inside them and they may always be attracted to the island! so having a whole bunch of these people on a plane is like a homing beacon really).

So what happened between MiB and Jacob? MiB got tired. He knew what humans would eventually do. Remember he came from 1970ish so he knew about World War 2, Vietnam, and all the corruption and death that would come in the coming millenias. So he decided to hell with it and just wanted to die, even if it meant releasing the exotic matter onto the whole world, wiping it out.

--THE CANDIDATES--

The Candidates are Jacobs insurance. He can try to keep MiB subdued for as long as he can but he knows MiB will find a way to kill him eventually. There is no secret to killing Jacob. He is simply a man but a hard man to kill because of what he can say to you before you kill him. (Richard being a perfect example, MiB just simply asked him, that's the only loophole, very simple). Now Jacob's goal is to find people who will WILLINGLY trade places with MiB and keep the world safe. MiB gives up that any such people exist. Jacob and MiB are on the same side. MiB wanted Jacob dead because Jacob blocked the road for MiB to get off. MiB could leave ANYTIME but Jacob simply stood in the way. Now with his death Jacob is hoping one of the candidates will realize their role and continue to save humanity....

....Willingly! as opposed to being forced, which might be what MiB is attempting to do with the Losties right now. The rules state that MiB can't kill those exposed to the islands power (Jacob touched the candidates. Perhaps Jacob and MiB are literally connected by the energy and Jacob is like the iron ball around MiBs ankles and the Candidates are smaller versions of this ball but they haven't realized their power yet). Maybe he has found a loophole and will use the plane to gather all the candidates and fly them into the volcano to crash and kill them all or have one of them willingly replace him for then he can be free of being bound. But I think this is where Jack will come in and save them all somehow.
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--WHAT IS THE ALT?--

I think the alt really is simply an alternative timeline but its purpose is not to carry the story forward but to show the point of the show. Remember how the producers initially created Lost as a mini-series but then extended it. Well that mini-series might have just been the alt and in the end it will show some grand point about love transcending time or something like that. So the main show is about the story and then the alt is the outcome that we will at the end be smiling about because we finally understand the message Lost was all about.

OTHER SMALL NOTES:

There's another scenario that could prove true and that is Jacob could have been/or is in the same position as MiB. They might have both fallen in the exotic matter but in different ways or Jacob was once stuck just as MiB and tricked MiB to taking his place in order to find a permanent replacement, I don't know. Another twist might be that the series finale is actually how MiB was created meaning one of the Losties is MiB and they get sent waaaay back in time and this all begins again. I'm not entirely convinced that both Jacob and MiB came from DHARMA times but I think one of them did and the other was in the past. I don't know how these would play out but they are interesting alternatives to what I suggested.