I found a fairly serious exploit for arena. Not sure if the beast cause of action is to post it here, or if there is some how to report it without sharing it with everyone.
You could contact support: https://gemsofwar.zendesk.com
But it might have been reported already, so check this thread first:
Thanks. The problem with people having extra stats in arena is already posted, but I submitted how to get them to support, as being able to get extra stats in arena makes it way too easy.