General Leo Edition

Something I was wondering was if you'd be able to put Shadow back as a playable character full time with another hack (mod, really.) that allowed you to use a certain item to place 'temp' characters in your party. I believe it's featured around here somewhere, but not quite sure where.

I think you are talking about Hatzen8's Guest adder patch: http://www.romhacking.net/hacks/1009/