[Suggestion] Equipment that alters other items' bonuses

This would introduce some complexity to equipment selection, making it less obvious that any one item is "best" for any given action (e.g., fire spells).

Example:  A combat tiara that imparts a charisma bonus, but also enhances the combat bonus of other items; so, that one item alone does not in itself provide the ideal bonus, but it acts as part of a set, and swapping it out alone won't necessarily be the best choice.