Since some things in XIII-2 forshadow alot of what will happen in Lightning Returns, i will put it into spoilers for those of you who haven't finish XIII-2 or want to get into the series unspoiled:

 

 

In the datalog for XIII-2, it says that the people trapped in the Coliseum(Like Snow Villiers) would be trapped there until the "Day of Reckoning" occurs. The Day of Reckoning is basically when Time is destroyed(so it occurs in the ending of XIII-2). Then those people would be freed, and would join in the Battle between Bhunivelze and Mwynn. The Arbiter of Time also stated that there would be a great battle at the end of time. So after the "event,"(being the Day of Reckoning) the warriors and gods of history would duke it out(hence why Snow and the other people trapped in the coliseum are freed). Also the B-whatever-guy(guess who that is) would be the final boss. So, we may end up fighting Bhunivelze in the end, even though he gave Lightning the power to save the people in the world.

 

 

If this is true, then the ending will completely blow our minds.

I played both final fantasy XIII and XIII-2 but I really feel like I missed something with all this talk of Bhunivelze, other gods and whatever. 

I thought the people in the Colosseum were all clones of great heroes of time, so wouldn't that mean it is possible that Lightning in Lightning Returns could be the one from the Colosseum?

I thought the people in the Colosseum were all clones of great heroes of time, so wouldn't that mean it is possible that Lightning in Lightning Returns could be the one from the Colosseum?

They were but not all of them. Snow and the Arbiter of Time were the only ones who weren't clones and where there in the coliseum for one reason or another. Light, Amodar and Jihl are clones and the numerous FF5 bosses in the coliseum are most likely clones as well. Since Snow is already there, odds are he'll join in the fight and the AoT could be running the new arena in LR. Presumably, they could get involved and join in the fight but the clones probably won't.