Board Thread:General Discussion/@comment-27539589-20160828041327/@comment-28738889-20160828051200

If you have Character XP Augs, those help, but by far the quickest way to level a character up (and simultaneously farm credits) is Bonus Battle 6 (the star battle in Area 6 in Single-Player). You probably don't have the best characters to clear it all the way through, but if you have E7 bronzes, that's the easiest way to clear Mirror Match.