The game can get boring once you start going on that never-ending rampage that culminates in a WC. That's why I vote for these Papal Conspiracies:
1. Edit in some sort of depression that crashes your economy, putting you on the defensive and making the game more challenging.
2. Assassinate your Pope and mod the game so that power-hungry cardinals carve up your empire into different bishoprics, leaving you to reunite the Catholic world.
3. Simulate the actions of your Pope; seeing as how he's got horrible stats, play the game as how he would. Make diplomatic and political blunders, screw the economy, and fight poorly.