Can your factions characters..

Go into the prophecies anytime that they want to? Or is it like with the prophecies, they have to get to a city, and do a quest?

they have to go to kaineng center, and do the quest "chaos in kryta", when i entered kaining with my newly made assasin a small text appeared telling me that i had to talk to guardsman chiempo.

If you own both games and you have a faction-born character, than to get into the prophecies campaign you do do a quest, but like the prophecies quest to get into Cantha, it's not really worthy of being called a rela quest. Basically you talk to Guardsman Chienpo in the northwest corner of Kaineng Center, he'll give you a quest and all you have to do is walk out to the docks and talk to the boat captain and a couple other ppl standing near him. After that you can freely travel back and forth via the boat travel.

Ahh, thanks. :]