Hey, BB was Prime's character, all I did was give him the green light to let his imagination go wild. All I did was release the BBeast...

But back to the topic at hand, a certain theme would be good so long as the players can come to a conclusion. And on the topic of Grimms, there will be "Additional" varieties that are set in canon, I.e. monsters we made up for the purpose of the RP.

Personally I liked the idea of partners that made up into larger teams, however there was always the issue of naming them. Just my thoughts. As for the themes themselves, I always had a thing for tarot themes, though not much in any ways to symbolically represent them.