Lost Season 5 Episode 12 - the smoke

Finally the smoke's identity is explained.  Its commonly called the judgement day.  Or the thing that will show you flashes of what you did in the past and decide for your fate.

The ones that save you are called angels and the one who took your life are devil.  Here, its just the smoke.

Its commonly used in a few other sci-fi too where some sort of smoke form around you become walls that display flashes of your sins or deads.

In Chinese culture, they are called Cow Head Horse Face, who will escort you to the court and execute the punishment after judgement.

There are a few other implications too.  It was summon by pulling plugs on a draining system, it came from underground.  Its actually not in the temple but underneath a hole beside it.

came from underground : it is inside and a part of earth, most likely the earth itself as if the earth is the ultimate living creature for all life on earth.  Earth breath life into us and earth can take it back.

summon by draining system : only when human really spoil the world terribly, it has no choice but to come up and do some clean up.  we live on the surface of the earth.  we see things on the surface.  when we don't want to see something ie our own waste, we simply burry it or drain it away.  Same goes to dead bodies and dirts.  We will drain so much until it has to come out to judge us even before the judgement day arrives.

we don't get judged in heaven ( represend as temple).  we get judged at the entrance to hell ( as dark undergrond ).  Only after being judged, you will then be sent to hell or heaven.  Sometimes, you may be sent back to life as in reincarnation - just like Ben.  Reincarnation also implies some unfinished work and comes with some taboo you must adhere to this time.  A chance to re-live your life.  Ben's is to eliminate his intention to kill John to get back in charge.