Fire & Ice:
Fire and Ice are two hidden opponents in One Player Game.
The Fire&Ice moves are described for each separate bot in the HAR area.
Fire: is only available from the Fire Pit arena.
And you can only get to him by executing a Fire&Ice move after a destruction.
Fire is only available at Champion or higher difficulty,
Fire has the 3rd enhancement for Katana, and can fire the Fireballs.
Ice: After defeating Fire you can do a Fire&Ice move again to get to Ice.
Ice is only available at Ultimate difficulty.
Ice has the 3rd enhancement, and can fire the Icefreeze.
  Screenshots:
Fire... & Ice