I had a question in D&D 3.5 regarding making items. I had this concept for a particular weapon which, while made of cold iron, could be sheathed in silver when necessary. Basically, the issue that came up was that I wanted a weapon useful against a wide range of evil outsiders, rather than just demons or just devils. I know silversheen can do it as a one-shot, but is there a possibility of making such an item? What would be the cost?
I admit I am not very good at making magical items, so if anyone could help me with this I would be exceedingly grateful.