Play as Gourki
To play as the sub-boss, press Up, Up, Down, Down, Left, Right, Left,
Right, B, A at the title screen.
Play as Reiji
To play as the final boss, press A, B, Right, Left, Right, Left, Down,
Down, up, Up at the title screen.
Reiji Transformation
Enter the "Play as Reiji" code. When your life bar is about one-third
full, press R and L together and he should transform into Yami or Hikiri.
Cheat codes from Bill's Cheat Pages http://www.angelfire.com/ca2/billscheats/
