Well, technically we still have Weiss if she/he/it/they/bagel ever posts an actual character sheet.

Hopefully they pick a good letter... honestly another M would be good, because R-F-J-M kinda sounds like "Rough Gem." It's a little pretentious, but also symbolic of their nature as students.

I seriously can't think of any other good combos, not unless we put F in the front, but whoever goes in the front is usually the leader, and I don't want Felix as a leader. I don't think he'd be good at it.

However, if we break the first letter rule, then an O would be good. F-O-R-J "Forge"