My players have decided to explore the Shimmering Veils of Pride first, which means we're coming up on the mirrors of opposition at the entrance. How should I make these function in the 4e conversion? Simply copying their entire character twice seems like overkill - that's a lot of extra abilities and powers that probably won't be used (and, if they were used, would probably represent a much greater challenge for the party than they can handle). I could also create new monster stat blocks for each PC, in anticipation of their activation of the mirrors, or I could turn each character into an NPC stat block (using the class templates presented in the DMGs). The last option is to simply make each PC-reflection monster the same: a generic mirror entity monster that simply wears the face of whichever PC brought it forth.
What do you think? Some options are clearly more work than others, but would be more flavorful. I'm currently leaning towards the NPC-stat-block solution, but this poses some difficulties for a published conversion: there's no way I can know what your own party is comprised of. If I decided to use customized stat blocks for each individual party member, you as the DM would have to create them yourself to match your own party once you reached this point in the adventure.