After defeating Grand Sphere, the Ultra Warriors returned to Earth. However, they did not hurry to remove their transformations.
Grand Sphere should have been destroyed by Dyna in the original timeline, but it had appeared ahead of schedule. Alongside the appearance of Sphere, the Ultra-Ancient faction represented by Luke immediately emerged. Fully armed, although they claimed to be coming to Earth's aid, nobody was foolish enough to believe it was just a coincidence.
Yet, this really could not be blamed on the Ultra-Ancient humans of Luke's faction. When Yin Xi, the ultimate variable, appeared in this world, everything he did brought unknown changes to it. Many things naturally shifted, and most of these shifts were unpredictable and irreversible.
Chapter 73