When I play Arena mode I always see players that are using custom card backs such as the heroic card back, legendary card back, or any other else, I also see players that are using custom hero avatars.
I have various card backs and I'd purchased avatars, however when I play Arena I always see that I'm using the same card back, every time that I enter in Arena it assigns the same card back and that is suspicious because seems that other people can change their card backs to play Arena, but I can't see any option to change my card back neither my hero avatar, why?
Best Answer
On PC/Tablet
From the main menu go into the My Collection tab. In the top right corner there will be a tab for card backs and a tab for hero portraits.
Simply right-click on the one you want to choose and then click Make Favorite.
On Phone App
Once again you want to go to My Collection but this time you'll have to click on the drop-down menu in the top right (it should default to Druid). From there you can select to view your collection of card backs and hero portraits, and once again you simply select whichever one you would like to use and press Make Favorite.