1. Oryxs sister Savathun (some suspect to be Mara Sov still alive since she is a God of trickery and cunning) 2. Oryxs sister Xivu Arath who is all about sword logic and strength 3. Quria Blade Transform (the vex mind who first saw the hive gods and changed the vex to be able to worship sword logic and the darkness) 4. The Cabal Emperor (who has been alluded to recently as being contacted after we killed all their great commanders) 5. Possibly Variks since he has been mentioned recently as wanting to unite the fallen houses under the banner of house judgement similar to what Skolas attempted with the wolves. However I think someone from the House of Kings will take command PS read the books of sorrow in your grimoire enemies section to understand how great of a threat the first 3 are