I have been leveling some charecters on the new server as well as the first one. I managed to get some pretty good names, that are quite unique. So, you can imagine my surprise when I see my name, on a charecter I was about to fight in arena. Not only was it my name, but it had my weapon, armor, and even was the same class and level as myself!

So this leads me to believe that not all the battles are active people, and some times, they are just charecters that are around the same level/CP as is needed to complete a set of 6, and just operated by the game themselves.