How do you get a sonic chao on sonic adventure 2 battle

This is really difficult to do (i've never been able to)

hatch a normal egg with sonic.

raise with shadow so that it becomes a neutral chao when it evolves

once it evolves into a neutral chao only enter the garden with sonic and only feed it green chaos drives.

eventually it will grow the spikes and change colour

(change characters for other chao types eg. hatch knux. raise rouge power only)