Remember the 4th season episode "Something Nice Back Home"?

Jack is in his office when the smoke detector goes off and then Christian appears on the couch.

If this wasn't the smoke monster, who/what was it?

I think Christian Shephard is someone/something else. Not Jacob, not Smoke. Even Claire made the distinction.

Jacob

I think Christian is Smokey's version of Richard in that he is a mediator of sorts for Smokey.

I think Christian Shephard is someone/something else. Not Jacob, not Smoke. Even Claire made the distinction.
Agreed. I think we're being led to see a third entity in play. Like seeing the bloody kid. That wasn't Jacob or the MiB.

Agreed. I think we're being led to see a third entity in play. Like seeing the bloody kid. That wasn't Jacob or the MiB.
I don't necessarily disagree with you, but how do you know it wasn't Jacob?

MIB is trapped but maybe not "on island"....he confirmed Jacob took his body so maybe he's trapped cause he can't get back home, home being his real body! Jacob took his humanity....he's trapped cause he can't be human anymore??? Maybe he's like a prince in fairy tales...you know like prince frog or something like that....he needs someone to love him to break the curse but his appearance is disgusting so no one loves him.... he said to Ben "i'm sorry you need to see me this way" so he's not very proud of his form... he became a monster and no one loves him so he doesn't love people either...he needs someone to love him to break the circle! Actually he can't stand circles! lol

Agreed. I think we're being led to see a third entity in play. Like seeing the bloody kid. That wasn't Jacob or the MiB.

I don't necessarily disagree with you, but how do you know it wasn't Jacob?
You're right, we don't KNOW. But we've never seen evidence that Jacob takes the form of the dead.

Also Christian appears to Michael on the freighter and tells him "You can go now".
If MiB is trapped on the island would he be able to appear on the freighter. Can he travel across water?
Which makes me question if he was really responsible for the Ajira survivor deaths.

When we first saw Smokey in Locke form he was on Hydra island, so he can definitely travel across water.

Maybe he's trapped on EARTH and wants to go home to HELLLLLL *lightning crash*

Agreed. I think we're being led to see a third entity in play. Like seeing the bloody kid. That wasn't Jacob or the MiB.
There is a reason that Jacob and the MIB are on the island, and since they apparently have limits to what they can do and are somehow bound to the island in terms of having to be responsible for what happens there I'm sure that it is that some 3rd party set limits on them. .

Maybe Jack was just tired and the Christian Shephard vision was just a momentary hallucination?

A bit like when Claire appeared in Kates Dream and told her not to bring Aaron back to the island - same sort of thing?

Cheers, Ana