I noticed something, I think, nobody did earlier.
I found out that entering the arena was in auto-mode, which is a bit crude.
I'd like to suggest making a button to help us enter the arena by our own will, not the system's will. This will help and give more time for the peeps to improve or change their equipment before entering the arena.
This is something happened in Gears of War. Why not here too?
Thanks, and I hope I helped a bit to improve this game