I've had this idea for a while, inspired by a couple of different sources, and I'm looking for some advice. What I'd like to do is develop a mechanic that when the party finds magic items that maybe can't be used or sold have a way to reuse that magic that is contained in the item. Example: party defeats evil cleric and now has a +3 unholy mace. what to do with this item. can't sell it, because the market for the item is evil creatures/people. seems a waste to destroy it. why not come up with a way to remove the magical essence and place it into a new object of equal or lesser strength with different properties? maybe have a flaming weapon? or switch it to a holy item? or go with bracers or armor?
The other idea is to drain the magic from the item to cast spells. essentially using the magic in the item to power your spells.
Any thoughts?
Allowing a crafter to use magic items as the raw materials for creating other magic items seems perfectly balanced and appropriate to me. I've done it in games I've run, and never had a problem.
Draining an item to cast spells seems like it could cause more problems than it's worth. For example, do your casters really need more spells per day, or would that just make them dominate the party? Also, depending on your group's policy on loot distribution, would the casters just end up getting all the magic items simply because they can use any item, while the hitters have fairly narrow needs.
Sounds like an Artificer to me. I've recently more-or-less finished making an Artifice Mystery for the Oracle class from the APG. One of its available revelations lets it use magic items as raw materials. I also think it'd be balanced enough to just give the ability to everyone or make it an available feat:
Transmute Item
You gain the ability to break down magic items to their most basic components.
Prerequisites: Craft Wondrous Item
Benefit: As part of magical crafting you may use any number of magical items as raw materials to create new magical items using half of their base value to help cover the gp cost of your new items. If the gp gained in this way is more than what is needed for the crafting, the excess gp is lost unless you spend an extra day (equivalent to 1,000 gp base price worth) of crafting to make the extra amount into actual gp. This requires a separate Spellcraft check (DC 10). Alternately, you may simply spend that same amount of crafting time to break down any number of magical items to gain half of their base value in actual gp using the same Spellcraft check. You must have the appropriate item creation feats required to make the items to perform this ability on them.
You can drop the actual gp part if you want. It might be a little too powerful as a feat. Maybe also make Improved Transmute Item to be able to do that part.
We go with the gp worth when sold to cover the material cost for a "matching" enchantement. Ex.: I would allow the +3 unholy mace to be used to turn a currently +1 sword to a +3 holy one and also empower a MW hammer to +1. I would require the participation of a Good-Divinity influence.
I was inspired by reading about church-bells being taken and reforged for other factions during the crusades.
To note another option that was offered by James Jaccobs:
The "Good" churches could be motivated at aquiring the "Dark-items" to prevent them from being used further (probably even to destroy them) and pay a "proper reward" (i.e.: sell worth).