Character 6 of 50 for my new Marvel expansion set is a classic X-Men villain I always thought deserved better in this game:
(https://orig05.deviantart.net/7e40/f/2017/253/6/2/the_blob__fred_dukes__character_by_overpower_3rd-dbmzmjw.png)
Specials in my gallery (http://overpower-3rd.deviantart.com/gallery/).
i guess the BoEM could've had their own icon, but it would probably not fit on some characters. you have a limit of 3 Affiliations per character card, and i agree that any more would take up too much real estate. nice take on the grid.
On top of that, there isn't a single Brotherhood member who wouldn't also have an X-Men Affiliation.