it should be Kabr. Corrupted and twisted by the vex, bringing with him an army. he helped them figure out how to make the technology they have exist outside of the Vault of Glass, took command of them, and is out for revenge on the traveler for abandoning him in the Vault. the final raid boss should be him. and it should take place in the city. for the duration of this DLC you should see other guardian ships and a giant vex shape ship along with smaller drones flying around the traveler, the city burning and such. make the city a part in the raid, and the vault of glass and the deep vault a patrol area, because the VOG is much bigger than it is in the raid. MUCH bigger. it scales most of the underground of venus. [spoiler]boom[/spoiler]