ok I havnt been able to prove this true or not because I still have some stuff to do in konquest, but what if the keys unlocked jail cells? I mean cmon you need keys for cells and it would make sense if you look at it that way. Im not too sure if it will work or not but maybe you use shujinko and go up to them and press L2 or something like grabbing a weapon. this is just a guess and go ahead and post what you guys think of the keys too. thx!