We have a doubt about crossing a defense more than one time. My robot have passed a defense from the neutral zone to the enemy courtyard, if I want to go back to the neutral zone, can I pass throw the same defense? Or I have to cross the enemy secret passage?

Hi Brazil!
You can’t use the secret passage to circumvent the defense (G20), so you would need to go back through the OUTER WORKS.

G20 ROBOTS may only enter or exit their opponent’s SECRET PASSAGE from/to the opponent’s

You’re only allowed to bypass the defenses through your own secret passage, not your opponents.