Hi,
You are missing a key concept with your question:
the object you create on one side, is the SAME prefab as the one that is instantiated on other running instances.
So, you can have an Fsm on that prefab that when starting, ask the question "is mine", using the action of the same name, and if false, then you know you need to add yourself to an arraylist.
Do you understand the concept of ownership within a networking system? the "PhotonViewGetIsMine" action is critical to understand here. Have you studied the sample provided to see how Photon is integrated in PLayMaker?
I haven't had a look yet at offline mode, but it's on my shortlist, so coming very very soon.
bye,
Jean