Ok first of all i searched and found nothing, so if its repost (like mostly everything these days) then IM SORRY!.
So you have just gathered a grp of buddies or a friend to boost you in BRD (or your boosting) and you dont want to do the BRD arena and dont have the key to get furter heres a trick you can do.
Enter the arena and step into the middle and that damn ugly dwarf spawns and begins to yell till you get a headche lal.
The gate you came through closes and another one opens were either spiders,scorpions, flying gnomes or what ever comes out of there (lol) you run here.
then run up like this
Stand ther for like 5 min more or less and the gates should open again.
Hope it helped..
Atleast i dident try to repost, BUT if it is a repost then gief link and ill delete.
~ Michael93