In my Rise of Darkness Quests, there is an Artifact called the Phoenix Staff (which was named years before we became acquainted). On first find, it is similar to the Wizard Staff, but it has a setting on the top where magical stones may be placed to enhance it. An additional ability is added depending on the stone that is set in the staff (which may be changed between quests and often requires proper cutting before their initial use). The staff may be used by anyone, but the additional stone enhancements may only be used by the Wizard... thus far. I may have Character specific enhancements later, but will likely keep it Wizard only and just create an Artifact that has Character specific attributes. In fact, I've decided that's what I'll do. Keep the Phoenix Staff Wizard only, and design a separate Artifact with Character specific attributes. That'll keep'em Heroes fighting amongst themselves for a while!
Any who, back on topic, I like the idea the Scepter and it will make for a great addition to TIA. Customizable weapons are always an interesting idea as they allow for something new each Quest. Three Combat Dice may be a little overpowered with additional enhancements.