I decided to mess about with costume change macros, and Dyna Green seemed like the best one to start with (Altered Brute will also get them once he has a few more costumes). This gave me motive to use his un-altered fourth costume slot for a "secret identity" outfit as a badboy biker who's initially too cool to hang out with the other Dynamen.
( Dynamen? We're merely six good-looking Japanese teens from all walks of life! )