When watching the Dragon Ball Super anime, it’s never easy to tell how Goku managed to master Ultra Instinct in the final moments during the fight with Jiren. In fact, the series didn’t share this information with viewers, so as it stands, most of us have no idea.
That’s where the manga comes into the picture. The latest chapter explains very well how Goku finally mastered the Ultra Instinct form, and it makes sense. You see, our beloved Saiyan realized that he had to "get rid of unnecessary emotions" from within his heart.
Not only that, he told Jiren that his heart "as calm as the gentle streams of Mount Paozu." From what we can remember, both characters did not have this conversation in the anime, so this is completely new and refreshing.
As per usual, Jiren attacked in a rage and actually sent Goku to the edge of the ring. Interestingly enough, Goku couldn’t keep his composure and lost the mastered Ultra Instinct form.
It wasn’t a surprise because he’s a man in training, and this new form is quite difficult to master and keep under control. Bear in mind that only the angels have mastered this form, so Goku has done what every god of destruction have failed to accomplish.
As it stands, then, reaching the final mastered Ultra Instinct form requires a state of mind that is calm and free from emotions. It makes us wonder if he’ll use Ultra Instinct against Broly in the upcoming movie.
Fans of the manga are at a crossroads right now because the Tournament of Power arc is coming to an end. There’s no word if things will continue beyond that, but as time goes by, we shall find out.