Auto Battle was implemented to help or tend to players who want to do more while playing Brave Frontier and is exclusive for the global version. Though the Auto-Battle will not replace the optimal way on how you play your team or do more Sparks for you, this is only a means of giving you an opportunity to allocate less focus on easy or normal missions so you can still do other things while playing. The gumi team still believe that manual gameplay is still the best way to go for Brave Frontier and there is no alternative for it.
You can activate the Auto-Battle feature by tapping on the Auto Button during battle.
Note: Due to the popularity of this feature it was also implemented in other versions of the game making it only the first in Global Server.