For some reason most LOST fans have come to the conclusion that in order for MIB/The smoke monster to turn into someone else they must be dead (Locke, Christian, Yemi) But I think logically he really can turn into anyone simply by scanning people and using their own memories against them. The most obvious, clear example is Walt. All of Walt’s strange appearances had to be MIB, and we know Walt is fully alive; First as a captive of the OTHERS and then alive off island. Before being killed by the smoke monster Eko had several visions of his past, and we are pretty sure this were all caused by the smoke monster, yet at one moment there were 3 different people visions (the 3 drug lords) surrounding Eko, this proofs MIB’s “shape shifting” abilities are not limited to one appearance at a time, (which explains how we saw Richard’s wife and the smoke monster at the same time in Ab Aeterno). In the same Eko episode we also saw a “vision” of the little alter boy, as far as we know he is not dead. Besides all of this people were outside the island, so how could Smokey know how to look like them? Simple he just needs to use the images that he takes from people’s minds when he scans them. We are sure Yemi was the smoke monster, but the first “appearance” of Yemi was actually in a dream that Eko had, so this proofs that MIB can just get inside people’s minds as simply as a “dream”. So if MIB can turn into anyone living why not do it? Well I think MIB prefers to intimidate/scare people into doing things, and appearing as someone dead has a lot bigger impact than someone alive, dead Alex appearing to Ben convinced him to kill Jacob, if a fake Jack would had appeared to Ben… probably would not have had that same impact….
Ok now that I pointed this out, I am going to get into my actual theory. When I first heard last week's episode was to be named What they died for, I misread it thinking “WHY they died for” thinking they were going to explain why many characters died, but they only explained WHAT it was all for, the heart off the island, no problem with that, but it got me thinking of the WHY, and the answer simply was because they were candidates and MIB found ways to kill them indirectly, so here is the run down.
Note. I used Lostpedia to determine if they had their names/numbers on the cave wall or lighthouse and thus were “possible” candidates
Boone (Carlyle 226) : Boone died falling off with the plane, how did he get there? Because Locke had a dream sequence where he saw the plane crashing and with Boone telling him “Theresa falls up the stairs” (to point the obvious Boone was still alive when this “vision” happened) Telling Boone about Theresa made him a believer that it was their destiny to find the plane…leading to his death. Only way Locke could had known about Theresa was if it was a vision made by Smokey after he probably had scanned/read Boone’s mind.
Shannon (Rutherford 32): She died because she ran off following “Walt” right to where Ana Lucia shot her
Ana Lucia and Libby: (We are not sure they were candidates even) but that one was Michael own doing, like someone told Michael, no one told him to kill them.
Locke (almost): I believe that the vision of Boone that Locke had inside the sweat lodge telling him to rescue Eko from the polar bear, was a vision produced by MIB to try to get the bear to kill him, it failed.
Mr Eko: He was not a candidate to begin with. We know this cause the OTHERS tried to grab him during the tailie’s first night and because Smokey killed him directly. But why didn’t Smokey kill him on their first encounter? Because he wanted to manipulate him into doing his dirty work like kill Jacob, just as he later manipulates Ben into doing so; but unlike Ben who was sorry for Alex‘s death, Eko did not regret what he had done. When he saw Eko could not be intimidated he disposed of him. To skip ahead, I think MIB was prepping young Ben from a young age, first appearing to him as his dead mom. This led to Ben’s meeting with Richard and eventually becoming Leader. Eventually Ben of course killed Jacob.
Nikki (Fernandez 321) and Paulo: Appears that at least, Nikki was a candidate. They both were actually accidentally killed by Hurley and Sawyer, being buried alive. They were in reality just paralyzed by (confirmed by the producers) by the smoke monster in the form of the Medusa spider. Interesting to point out that smokey can turn into “other species” …… Hurley bird explanation maybe? ….maybe even Kate’s horse?
Naomi (Dorrit 27) killed by Locke after he was told he “still had work to do”, told by Taller ghost Walt (I‘m sure was another manifestation of MIB) But why didn’t MIB just let him die in the Dharma grave? Well because he wasn’t going to die, and since Locke was a candidate he wasn’t going to be able to shoot himself. Besides I think he had bigger plans for Locke now.
Charlie (Pace 195) Charlie probably was just destined to die like Desmond foretold….unless ( I highly doubted) Desmond’s supposed visions of Charlie dying were lies produced by MIB to convince Charlie he had to sacrifice himself which could actually explain why Claire getting off the island vision never happened…..
Michael (Dawson 24) indeed a candidate cause he couldn’t kill himself. He died trying to postpone the Freighter bomb explosion. This one is weird cause it appears that MIB had nothing to do with it….but its really weird cause before he died the whispers are heard and Christian appears to him. Maybe it really was Christian’s ghost in the form of the whispers. But Maybe, MIB does not have to be present to produce an illusion and could do it remotely, sort of like the dreams he can produce, he can engrave himself deep in people‘s minds. This could explain the Christian on the freighter and even in Jack’s office hunting Jack into coming back to the island. And actually this could also explain the Libby dream that Michel had, which was one of the things that hunted him and made him return to the island.
The rest of the Candidates: From this point on MIB (as Christian) manipulated Ben/Locke into pushing the frozen Donkey wheel. This led to a series of events where it appears that only the candidates time traveled (my explanation on why no OTHERS time traveled) Most of the beach survivors were killed during the flaming arrow attack; and after all that time travelling, in the end we were left with only 5 candidates. However we have 4 oddball time travellers; Kate, but she was a candidate in the end; Rose and Bernard, but maybe they were candidates but maybe stayed in the 70s and are dead now; And Miles…. that one honestly I do not know. In the end though, MIBs final plan was to finish them off in the sub, which almost worked….
And some final observations… Dream Horace telling Locke where to find the directions to the cabin probably another MIB vision. Flocke told us he first appeared to Jack as Christian because they needed water…..but I just find it interesting that the first time that Jack followed Christian, Jack almost fell off a cliff but Locke saved him. (and it would have been an accident not an willing suicide). And I also have my suspicions of Hurley’s “Dave” since he almost got Hurley to jump off the cliff….but that one WOULD have been suicide….. But that was season 2 and the suicide rule probably hadn’t been decided by the writers.
Indirectly I pretty much just explained most of the weird “visions” people have had, any others were just Hurley’s visions (probably just real ghosts) and the young Jacob that MIB and the candidates so. So this is my final LOST theory before the finale and this is the most logical run down I think we are going to get. So rewatch the series with the "simple" answer that MIB was behind most of the weird visions stuff and the series actually makes sense (up too the ALT world for now). Reader enjoy the finale, it was a blast.