Out of all the possible options, I will go ahead and vote for @Scotty.
Realist would be a good choise as well, though I think he would have to start taking things less personal wherever possible. Scotty has shown to be quite helpful and I think that he would be a nice addition to the team. Epsilon and Pain are just not quite active enough. Muffins has shown too little change towards being more professional to be a good candicate in my opinion.
That's just my feedback, nothing personal