[ SPOILERS ]Endings, Which one do you Prefer?

[Hardarm]

I prefer da Agrippa one.

But, what's the main ending?

I mean is there an ending that is supposed to be the "main" one the player has to choose?

Agrippa gave Daniel a suggestion, to cut his head and to put it in the portal, so I think that's the main ending. I mean what are the secondary endings and what's the ending that is supposed to happen at the end?

At the cells the player has one chance to escape
though if he remains 6-7 min in the cell game will end.

If there will be a sequel (dont think so),
FG must choose one of the 4 endings to continue, or else making a prequel, like the expedition in Algeria?