they are the heroes. They must prevent an eggman from finding a USB key that belongs to a secret project.If eggman finds the project he will be able to destroy the shadow project. so that's why it's up to axya to keep his USB key in his tail to prevent Eggman from finding it and so that's why.actually asfaxia can destroy uh shadow. because asfaxia a weapon to destroy shadow.so she avoids telling Shadow that she is a weapon.So that's why Axya must prevent it from falling into Eggman's hands