I haven't seen a thread about this, and whatever your opinion of the ending, it was certainly very interesting.

I personally liked it very much, and it made a lot of sense considering the inherent difficulty of writing anything to do with time travel and having it make any kind of sense. I love the little allusions to it throughout the game: Booker saying he ought to go into the prophet business, the seed of the Prophet, the fact that the music people are singing at Booker's baptism is the music you hear when you first arrive in Columbia.

I just had a few issues with it: How did Comstock know about the Mark of the False Shepherd when it never existed in his universe? Who is this Archangel, and how does he know so much? Why couldn't the Luteces kill Comstock without Elizabeth's help?

Those are, however, minor issues in what was a great ending to a great game.

Shameless plug for my review if you want to see my full opinion:

http://www.gamrreview.com/review/89914/bioshock-infinite

I wanted to make this thread :(

Anyway don't have time to make a post, so tagging for later. But the ending is simple on of the most mindfuck things I've seen in my life. Is simple a masterpiece. 

Finally have time. 

So, I think the game explains very well this whole multi universe travel subject. It doesn't throw you an extremely long cutscene explaining every detail of what's happening, the game gives some the basic stuffs you need to know and from there you start doing your own theories, something I really appreciate.

To try to answer your questions:

1) Comstock obviously knew about Booker because he took Anna from him. My guess is that after that event, Comstock was worried that somehow Booker would find him and take Anna (now Elizabeth) away. He probably was spying him and he knew that he had the A.D mark on his hand. Also note that the events of the game are one of many tries of Booker to try to rescue his daughter, Comstock (thanks to the trans dimensional travel the Lutece invented) knows about all the events in the game, if you look at room on the zeppelin (right before killing him), you will see all the sequence of the game in order, he knew he was going to die and he knew the cycle would repeat itself. That's how he became a prophet.

2) The Archangel Columbia is probably just a metaphor (or a lie) created by Comstock. His "Archangel" were the portals to other universes, throw them he saw multiple events of what could happen in the future. Like I said before, he knew about all the events in the game, he said it was the Archangel Columbia who told him those things, but it really just was the trans dimensional portals.

3) Maybe their objective wasn't really to just kill Comstock, but to reunite Booker and Anna, because they were responsible for all the events in the game, maybe they were just looking for redemption for their acts. 

Mother of god. Just finished it. Simply amazing. I was completely mindfucked at the end, but jesus. That's some terrific storytelling yet again.

I am actually still in shock over how well that game tied up. Legendary ending.

But only Elizabeth could open the tears, and only the Luteces could travel between universes without them. He trapped Elizabeth in a tower and executed the Luteces, so there was nobody left to tell him.

Plus, he does genuinely sound convinced of his Archangel's existence during the scene where he dies. Perhaps he had just deluded himself for so long that it started to seem real.

He probably used Elizabeth to control the portals. Comstock had her locked in the tower and they were doing experiments on her, so there's a probability that those experiments were for Comstock to have access to the tears.

I agree that Comstock was convinced about the Archangel, he basically believed his own lie.

Is this game linked to Bioshock in a major way? Girls name is Elizabeth and she was a lamb.. The man character in 2 was called Elizabeth Lamb. Bookers initials are B.d which could mean big daddy! And Elizabeth was his little sister in rapture, there seems to be a hella lot of correlations between the different bioshock games which I find fascinating.

Also was the baptism the pivotal point, where he had to make the decision, crossroads of sorts so by dying there, he was never Faced with that choice, therefore erasing the alternate possibilities? There are so many bloody references to the ending throughout the game, but they're so cleverly hidden, it's impossible to distinguish them and realise what the ending is going to be.

Also fontaine was very similar to fink, so I think there is a small possibility tht rapture is just an alternative universe of this damned cycle.

My mind is blown.

I am so confused... it's all so crazy. I don't get. What happened? What is the connection with Rapture? So Elizabeth ceases to exist in the new universes and therefore every universe? Is there a Columbia? What happens with those damned twins? The only time I have felt like this is when I watched The Prestige.

I am really sad the game ended. I was masterful. Among the greatest games I have ever played.

1) There's really no connection with Rapture (only theories like NotStan mentioned), it's there to show that there are multiple universes, Elizabeth said: "There's always a city and a man" mentioning that Rapture and Andrew Ryans existed in multiple universes, the same people, yet different.

2) Elizabeth and Comstock ceased to exist from every dimension. Comstock "born" on the baptism, so if Booker died there, Comstock could have never been born. At the same time Booker also died, so Anna/Elizabeth ceased to exist because his dad doesn't exist now.

3) Yes, Columbia did existed. But at end since Comstock died, Columbia (along with Comstock and Elizabeth) ceased to exist. 

4) The "twins" aren't really twins. Rosalind Lutece was hired by Comstock for the interdimensional travels, during her research she found a particle that let her speak with her other half in another universe (which is Robert Lutece). They both start experimenting until both found a way to travel to their respective universe, that's how Comstock was able to take Booker's daughter. 

But to answer your question specifically, the twins were murdered by Comstock, but they were alive in other universes and they wanted to take revenge for Comstock's murder, I also think they were looking for redemption for what they did to Booker. If you are asking that what happen to them after the ending, well they probably still living in multiple universes without problem.