Board Thread:Speculation House/@comment-34633327-20170712152648/@comment-26882656-20170712153357

One theory is that one mystery member is Dr. Merlot, the main antagonist of Grimm Eclipse. He is trying to mutate and evolve Grimm to make them more powerful.

"The Grimm are a superior species, fascinating in their biology, their unbridled, raw aggression and lack of sentience make them the perfect vessel."

I'm not sure how probable that is considering he is from the game, but he is a possible candidate.