As Windy suggested in the Development Pace Feedback thread, a good idea for a thread would be to talk of ideas for late-game improvements. He mentioned the Golden Horde that Baheshtur speaks of as an example of the Invading Army/ies theme. My only caveat for the GH is that it seems sort of reminiscent of the theme of the Khergits, and it might be kind of boring to have a new army enter into the game that is already like an already existent army.
An invading army of an entirely new faction would be something else entirely.
Also, I was wondering if it would be possible to have a Civil War possibility, where various rulers die and/or are assassinated, and the various nobles start a free-for-all among themselves. Of course, if your territories are already vast, then that might make your job of conquering Calradia even easier, unless your holdings are reduced as well. Then again, this might make it seem like you have to do everything all over again, so it might not be a good idea for that. Mostly, I like the idea of all the nobles breaking boundaries and going after lords near and far.
An invading army of an entirely new faction would be something else entirely.
Also, I was wondering if it would be possible to have a Civil War possibility, where various rulers die and/or are assassinated, and the various nobles start a free-for-all among themselves. Of course, if your territories are already vast, then that might make your job of conquering Calradia even easier, unless your holdings are reduced as well. Then again, this might make it seem like you have to do everything all over again, so it might not be a good idea for that. Mostly, I like the idea of all the nobles breaking boundaries and going after lords near and far.