For example, the ability to make it so it won't pick Legendaries for the battle. Other options could include locking certain region pokemon from say for example, a Gen 5 Random Battle. I can't think of too many more right now off the top of my head, but there are plenty I'm sure could be added. I love doing the Random Gen battles, but legendaries just kinda kill the fun sometimes. Especially when one side gets 3+ and the other has none.