Two ideas I had over the last 24 hours while planning a campaign. Nothing super-original, just potentially good ways to handle some ideas.
1: Bonds for the Villain
if you want the defeat of the big bad to be suitably personal to the party, one way to do this is to give them bonds with the PCs. While this has no mechanical effect (as NPCs don’t roll anything), it’s good for getting relationships going. You can also optionally give the party as a whole 1 xp at the end of session if a villain’s bond is resolved.
Give a villain that is linked to the PCs at least one of the following:
__________ used to work with me.
__________ is my family, though they wish otherwise.
__________ has something I dearly want.
I killed someone dear to __________.
2: Warring Fronts
For a campaign based around a war, I’m going to give both the enemy and the allied forced something like a Front. However, rather than a countdown to an Impending Doom, there is no set end point – each side records a major victory or the acquisition of a powerful asset as if they were Grim Portents. Once one side gets some significant amount more than the other, they win. From the PCs’ perspective, they can potentially try to engineer special missions or similar to try to get more victories for their own side, and pull ahead.