Well what can one say - the Arena is a good & interesting challenge SPOILT by the sheer clunkiness of the operation. I usually take a deep breath when starting the Arena - if it wasn't for the COA pushing to complete - I wouldn't bother.

Whenever you choose a Challenger to attack and then go and select your Guardian warrior - not any old warrior, you want to be selective - so sometimes it takes bit of time - saving the most powerful for last - then you've got the right one and suddenly - the system 'snaps' you back to the selection process??? It appears that when a previous attack has been completed it overrides what you are trying to do with the selection process. You are sort pushed into doing one attack at a time which is tedious.

So let's change it - when you select a Challenger and then go off to do your thing - the system should lock you into that - the system should allow you to do your selection WITHOUT interference. The system could put a 30 second / 1 minute. whatever timer on it - so if you rush off to get the phone, you are hanging the system up. 

Less tedious and quicker allround