MB was arrested and had most of his thinking equipment removed. Was placed inside the Sacred Key ship. After the Halo was activated, due to the lack of maintenance of the restricted equipment. MB gained control of the Sacred Key Ship, and since he had regained his consciousness and realized that humans were the recyclers, he wanted to fly to Earth with the help of the Sacred Key Ship in order to help humans recycle the Forerunner equipment. However, not knowing that the power of the Sacred Key Vessel was insufficient, MB had to shut down most of the energy facilities to save himself. The Sacred Key Ship also crashed on the Prophet's home planet. The Prophet War then broke out. The Radicals got control of the Holy Key Ship. After the Sacred Key Ship lifted off, due to not triggering the MB's control. The Holy Key Ship was converted into a Fraternity City. Eventually, the MB was activated by the Prophet of Truth Triumvirate and it was revealed that humans were the recyclers. the MB was controlled by the Triumvirate and the Star League-Humanity War ensued.
The OB arranged the remaining things after the Bug-Forerunner War. Also disappeared into the galaxy, most recent appearance: after the H4 episode, Dr. Halsey accidentally enters OB's home while searching for a way to open the Two-Faced Sacred Key. Go flip Halo for specifics