Scenario#2: Your local diety has been annoyed with your people's growing lack of faith. Play out a priest who has been given the impeding doom for your nation's athiesm, (decide the punishment) and have him try to bring about the nations faith again.
Scenario #3: Your empire has been decimated by an unstopable alien force. It is now at the edge of the home system of your empire. The entirety of the remaining remnents of your fleet is there. In this scenario, make your last stand. Bonus points for realistic outcome and battles.