Hello

On the end of Crysis you go back to the island to join Prophet.

Where do i faint what happened there? any novel or comic?

Also, is there any special video after the credits?

Thank you.

There exists a comic series of 5 editions detailing what happened right after Crysis. It svcks, really svck. Them comics were released by IDW publishing. Not worth reading them, just go to Crysis Wikia and read the summaries.