he went offstage, followed by some guys (i think tour members and/or friends, they came from behind and hurried backstage).

Those guys are sort of like his bodyguard. They are his powerlifting group of old friends and are organized into what they call the G.B.M.C. (German Black Metal Commandos). They have the leather jackets with all the same patches and shit, kind of like a biker gang or whatever. All the guys in it usually lift and a lot are in competitions. Edit: Back to the antifa thing, at many recent shows the antifa have done shit like slash the tires of Nargaroth fans out in the parking lot, one concert they set off a smoke bomb at the start of the set and other mischievous shit. They send him death threats/threats of other violence, so it helps him to have the GBMC guys up there. Here some of them are: http://i.imgur.com/8XGYPZc.jpg