is there a way i can check to see if i got all the secret Opponents?/

Comprehensive Guide to Battle Opponents (v2) has a list of all opponents—well, i'm not sure if it has the latest cash shop challengers, but as far as secret opponents go, it should be up to date. each one even has a link to a page explaining how to unlock them.

thank you i want to get more secret opponents... i have a few ands like to get same battles done