A couple of leaked achievements from Borderlands: The Pre-Sequel have been doing the rounds lately and they suggest that the game is going to get its own Circle of Slaughter-esque quest line.
The leaked achievements appeared on Xbox Achievements.
Have a look:
The achievements descriptions make “Holodome” sound a lot like Circle of Slaughter from Borderlands 2. Circle of Slaughter was an arena where you were tasked with holding off as many baddies as possible.