Head to (F-9) in La Vaule (S) and check the Reinforced Gateway for a cutscene.
Following along the right wall from entrance is the safest route, only Invisible is needed unless Truesight NMs are up.(the imps are truesight). Also, depending on the route, you may also need Sneak if you run into Lobison. It is a bit of a run.
Check the Reinforced Gateway a second time to enter the battlefield for Purple, The New Black.
6 characters may enter the battle with a 30 minute time limit.
There is a Level Restriction effect at the maximum level attainable, meaning no experience points loss from knock out, and buffs will wear off upon entry.
One must either be on this part of the mission, or completed it in the past to be able to enter.
The battle is against a Dark Dragon named Galarhigg.
Can be defeated solo by a majority of jobs at around level 75 and up using Trust. Extremely easy at level 85+. (see testimonials)
Upon victory on the battlefield a cutscene will take characters to (D-8) in La Vaule (S).