That could be awesome. I just picture a massive battlefield Thats only lit up by all the guardian's ghosts. Hordes of enemies from all parts of the game(cabal, fallen, hive and vex) coming together on one battlefield. Bosses can jump into the mix and it'd be a real battle for humanity. Just imagine all the guardians having to come together calling out incs on bosses and literally saving the last city on earth. Thats something I could play endlessly