Why would you want to defend Gauntlygrym’s throne room? Well for one thing, Cryptic is attempting to freshen Neverwinter’s repeatable content by adding variation. In this case, two different scenarios can play out each time you run the skirmish, and each scenario randomizes both the types and the locations of enemy spawns.
The devs have also added team scoring, so you’ll receive a performance-based ranking at the end of each skirmish phase. And of course, there are a various rewards for the skirmish. You can read about those, as well as the two scenario variations, by following the link below.
Source: Throne of the Dwarven Gods