I've given up on the Golden Strings for now as it will be a little while before they show up. I do have one character who is interested in taking up the Silver Strings, their opposite and good number. He's pretty new and thus has given me carte blanche to make up the powers of the Strings. The concept is that they're not so much a weapon as a tool for balancing things out. They're more about protection and cancellation than any sort of offensive weapon.
So here's a sketchy outline:
(-?) Silver Strings:
Description: The Silver Strings are a set of musical strings made of pure, untarnished silver that glitter faintly with a holy light.
Skills Affected: Performance
Protective Muse: ***This needs to be cleaned up.*** The Strings are a subtle weapon against evil. By playing an instrument using the strings, their bearer can use Performance to ward off malign supernatural influence. The bearer spends a fate point, and for the scene can use Performance to create blocks against psychomancy, possession, incite emotions, or similar mind-affecting or physically controlling supernatural abilities at GM discretion. This can be done as a supplemental action to other uses of Performance.
Divine Purpose: ***This needs to be cleaned up.*** They're a less aggressive item than the Swords, but still have a purpose. That purpose is to spread peace and to protect the innocent from supernatural evil. The weilder can use them for personal gain (IE, playing for money), but they cannot be used in a deceptive manner, or be used to harm someone who has not harmed an innocent in the bearer's sight (including, say, using Pointed Performance to hurt someones' reputation). Also, the bearer cannot use them to forge a mortal contract (so no recording deal). If the bearer uses them in a manner against their purpose, they immediately produce a discordant twang, the Performance roll fails, and they unstring themselves but do not break. The bearer will not be able to restring them until he proves his faith again.
Holy: The Strings are a powerful holy symbol. The touch of a weapon strung with them is like a cross, holy water, or other symbol of faith backed by the belief of their wielder.
They're Strings: The Silver Strings always take the form of a set of strings for a musical instrument. Their number, length, and the exact key of each string vary, but always fit the chosen instrument of their current wielder.
Good Vibrations: The Silver Strings are of exceptional quality. When played in keeping with their purpose, they add +1 to any Performance roll made using an instrument stringed with them.
Unbreakable: As an Item of Power, the strings cannot be broken except through a specific ritual dedicated to subverting their purpose. This protection extends to the instrument they are currently in.
I'm not sure on the power level of their Protective Muse ability. It doesn't seem as powerful as a Sword of the Cross, but I don't want it to be weak either. What should their final cost be for the package? And yes, it is intentional that Holy+Unbreakable allows their bearer to do a blessed El Kabong.