Thanks for your comment Inesdar. Keep them coming. Here's something for you to chew on. 

I would say the scepters have miraculous power...and I guess that means God is the one empowering them every time they are used. However, they do not work by God's "will" as much as the bearer's strength. By that I mean, they don't work only when God wants them too, but always work as long as the bearer has enough strength to be a conductor between the Spirit inside him and the "spirit" in the scepter. I don't know what I would call the power base within the crystals, so I am saying "spirit" with quote marks. 
I guess I see them as similar to our bodies. God made them with inherent powers and then we choose how we use our strength. God still has control over our bodies so that He can heal and use for His purpose, but we are still allowed in His sovereignty to become sick and sin. As creation groans under the punishment of the fall, so too could the utilization of His creation - the scepters - by being used for evil. 
As humans can be possessed by demons, could the scepters be possessed? My first thought is no, because I can't think of biblical evidence for a possessed item - only living beings. Are there evil places on this planet that when the scepter is taken there, its powers are replaced with evil? - Almost like the spirit of good was removed and then filled by seven demons (kind of like the story where if the house/body is cleansed without protection more demons will return than were there in the first).