Herobizkit
Adventurer
I, as well, threw out a massive spread of possible suggestions - I would hope some of them didn't apply to your group. 
All the stuff I took out? That's the stiff I call "DM Mas... er... uh... self-..." (I don't know if there's a grandma-friendly way to put it). Bottom line, that info is swell to you and only you - none of that information matters to the players, as it's all background info. How does your villain interact with your players _directly_? Do they have specific recurring villains that make them growl and shake their fists when the villain's name is mentioned or appears?
It's good to remember that players only have the knowledge gained by looking through their character's eyes - they don't know what you know, they never know the stuff they miss or encounters they avoid, and seldom care about anything that doesn't directly affect them.
I think the players might be frustrated at the scope of the campaign... "bigger and more deadly" is a common theme in D&D but maybe they're tired of 'you have to saaaaave the world'. Maybe they're done trying to save the world - so let them stop saving the world and have the villains 'win'. THEN, make a new campaign with new characters who have to deal with the fallout of their old ones. :3

GMforPowergamers said:Hec tor kar.... he was once a demon lord.... (snip) and that is the world the PCs find themselves in...
All the stuff I took out? That's the stiff I call "DM Mas... er... uh... self-..." (I don't know if there's a grandma-friendly way to put it). Bottom line, that info is swell to you and only you - none of that information matters to the players, as it's all background info. How does your villain interact with your players _directly_? Do they have specific recurring villains that make them growl and shake their fists when the villain's name is mentioned or appears?
It's good to remember that players only have the knowledge gained by looking through their character's eyes - they don't know what you know, they never know the stuff they miss or encounters they avoid, and seldom care about anything that doesn't directly affect them.
That's great, but if all they can do with it is "personally look for artifacts", what's the fun in having said wealth?As sanctioned knights they have more resources then any group in the world...
So your players are the only ones who can assemble the artifact... what happens if they fail? Are they even ALLOWED to fail? Also, are your players the only people in the whole world amassing power?Well I can't have someone else put together the artifact, it is too powerful.
I think the players might be frustrated at the scope of the campaign... "bigger and more deadly" is a common theme in D&D but maybe they're tired of 'you have to saaaaave the world'. Maybe they're done trying to save the world - so let them stop saving the world and have the villains 'win'. THEN, make a new campaign with new characters who have to deal with the fallout of their old ones. :3