Arena Select
To Access the arena select mode, hold down L1+L2+R1+R2 and then hit select at the Main Menu Screen. In the upper right hand corner 'Stage 00' will appear, press Right or Left to cycle through the numbers. Double digit numbers stand for diffrent battle arenas and single digits indicate the time of day.
Fight Zio Gigas
This incredible trick will put you in the number-one position in the tournament, allowing you to fight Zio Gigas. From the Menu Screen, move to the Password Option. Enter the password as shown with the upper and lower case letters:
X9yI47OMUGWNGXXkX
fPX3Xn3jYWWWaXXdO
Once you do this, you will be upgraded with the best equipment, and you will be able to access all of the different arms in the game. Fighting Zio Gigas is no easy task. He hits hard and can kill you in a matter of seconds!