At the moment TERA doesn't have multi-group raids, but this is supposed to change soon with the introduction of Nexus Traverse later this month as part of the Argon Queen expansion, that will accomodate up to four parties of five players each.

Nexus traverse shows what's on the other side of the nexuses in which we have battled for months: a series of three octagons featuring enemies of increasing difficulty.

The first octagon will feature a bunch of nexus trash mobs. The second will pitch players against two BAMs ("Big Ass Monsters", TERA's version of an oversized boss) that will have to be kept separate, because when they auras collide they become more powerful. The third octagon is home to the Nexus Sovereign, an immense BAM with wide area attacks and the ability to summon armies of adds.

The Nexus sovereign will drop enigmatic tier 14 gold equipment upon defeat. Personally, I have quite a lot of fun tanking the usual Nexus bosses, so I'm quite eager to slam my shield on the face of this Nexus Sovereign. You can enjoy a few screenshots below.