Updated Roadmap/Overview. It seems as though many of you are experiencing problems with The Only Real Stopper even after making sure you killed every enemy by playing through a second time. On the other hand, it's unlocking without any problems for other people.
If anyone has any methods or tips on this achievement, let me know!
Thanks to Xerofox for the romantically rambunctious signature!
Currently Playing: Halo: The Master Chief Collection
~ HALO IS LOVE, HALO IS LIFE ~