Having a SoulCalibur III save file on your PS2 memory card can actually have devastating results if you move, modify, or delete anything on your PS2 memory card. These include:
• Chronicles of the Sword side-quest becoming corrupted.
• Your entire SoulCalibur III save file becoming corrupted.
• All data on your memory card becoming corrupted.

Despite not being a playable character, KOS-MOS from the Xenosaga series can be created in the Character Creation system.