To input the password, go to "Super Heroes Mode" and in the map screen choose the 3rd option on top.

Effect	Password
Accel and G3-X vs Scissors	Ryuki, Kuuga, Decade, Agito, Blade, Kiva.
Agito vs Rider 1	Decade, W, OOO, Fourze, Wizard, Den-O.
Den-O vs Odin	Kuuga, OOO, Blade, Kabuto, Agito, Wizard.
Femme vs Ryuga	Kiva, Fourze, Den-o, Decade, Kabuto, Agito.
Hibiki vs Ryuki	Wizard, Kabuto, Den-o, Hibiki, Decade, Faiz.
Meteor vs Zanki	Ryuki, Wizard, Agito, Kiva, OOO, Den-O.
Saga vs Blade	Faiz, Den-O, W, Wizard, Decade, Kuuga.
Saga vs PunchHopper	W, OOO, Wizard, Den-o, Kiva, Fourze.