On the topic of villains with motivations to be in the story remember the three things needed to solve a mystery: Motive, Means, and Opportunity.
- Motive: Why do they want to do what you want them to do? What does it gain for them?
- Means: What resources do they have to help them achieve their goal? Magic items of legend? The back up of a whole nation's army?
- Opportunity: Why are they acting now? Are the stars aligning? Is it a magical comet that comes along once every generation? Is the moon turning blood red?
If you can figure some of this out then you can add a lot of flavor to your villains and maybe even cook up a B-Plot so the players feel the need to act now.
On the topic of Ten Candles, when will the Happy Jacks crew be tackling The Quiet Year?