Make hero or dark chao.
First, get any chao egg. Any kind. Now buy some hero fruits or dark fruits, 5 through 10 hero/dark fruits. Then feed it to your chao then wait til cacoon appeared, then volia! You have hero/dark chao!
I hope it help you.
More tricks, tips and cheats for this game are right here - Sonic Adventure DX Director's Cut cheats
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