Goku is the only mortal that achieved the Ultra Instinct just by absorbing a large amount of energy. His case is different because for some reason because he was shrouded in heat when he transforms. And not only that, he can’t really attack and evade or defend at the same time properly during the Ultra Instinct.
Spoilers from Todd Blakenship seem to indicate that Goku will be severely injured on Episode 128. And not only that, it seems like he will be out of stamina because of continuous fighting and all. It seems like Vegeta will be protecting him again even though it will cost him his life. In his most desperate moment, Vegeta will stand his own against Jiren’s ultimate power.
Vegeta will surely fall after this episode, as the title “With Noble Pride to the End! Vegeta Falls!” implies. But his last fight will surely not be in vain, as he will give all that he got. Even Goku will be entranced by the way Vegeta will fight against a man that is far stronger than both of them. While Goku watches and regaining his stamina at the same time, there is something that he will surely learn in the fight.
The title of the next episode is “Transcending Limit! Mastering Ultra Instinct”. The title is the spoiler itself and it seems like Goku will continue to surpass the Gods. This fight against Jiren and Goku might be the last one and will determine the winner of the Tournament of Power. Remember when Vegeta succeeded in avoiding Jiren and at the same time lands a punch?
Goku might find out how Vegeta can successfully avoid attacks from Jiren. And ultimately, Goku might have something from the fight that will enable him to attack and dodge at the same time during his Ultra Instinct. He might actually figure out Vegeta’s trick against Jiren and use it under his Ultra Instinct transformation.