Guilty Gear Xrd REV 2 is a standalone expansion for Guilty Gear Xrd -REVELATOR-, a 2D one-on-one fighting game, available on PS3, PS4, Arcade Cabinet, and PC:Steam.
REV 2 features a short list of system changes, two new characters -
Answer and 
Baiken - significant changes to the game's visuals and camera, a complete rebalance of the cast, expanded story content, and new stages. Rev 2 also received Balance Patch 2.1 which introduced further changes to the cast.