Ask around if anyone wants to give you an invite. There is an item to recruit people for this fight club instance. Basically a boxing match with 3 sets of variations.
I’ve already given away my invitation I’m afraid. The mission to do so dissapeared after that. Not sure if you get to invite more people at some point. Tho I’ve been told the message also randomly happens for some people in Agartha.
Wait what proxy?
Edit: Oh right! It is actually another instance. Basically a ruined version of London with an odd sky. You gotta buy the key in Tabula Rasa, after getting the invite, and then enter the floating box thing you also use to get to the rooms.
FWIW Shambala is actually popping now, though mostly during EU primetime, and often not with the full 5v5. Still! Some murder is better than no murder at all.