I think it's just a prank or someone can't wait to be banned. Our overlord is panda(GM-Pandora), of course it's better if other older players or panda herself were to answer this.
I think I'm finally going "home", renewal is fun, but there is really nothing like "heRO"...
Kyarorain, Shield Crusader
Erizabeth, Battle Sage
Derpette, Int Brewer
Katerine, Battle Acolyte
No, @who shows actual GM level (which you cannot fake), so that means it's an existing GM's "hidden" account used for GM work yet does not want to be distracted as people often randomly tries to PM GMs, even if they didn't announce themselves to be online.
Shouldn't be a "new" GM waiting to be announced cause Interns do not start as lv 40 GMs.
As Nami pointed out, GM-Overlord belongs to an existing GM, not one awaiting announcement. As for the question "who is it", I am not at liberty to say at this point in time.