Please watch the episode with any necessary subtitles before discussing: Crunchyroll / Daisuki / FUNimation
Also, please make sure to follow the Kanzenshuu Forum Rules. You may wish to review examples of unwelcome posts, as well.
-------------------------------
General Discussion for Dragon Ball Super Episode 129, aired 4 March 2018

限界超絶突破!身勝手の極意極まる!!
Genkai Chōzetsu Toppa! Migatte no Goku'i Kiwamaru!!
Limits Super Surpassed! Ultra Instinct Mastered!!
Summary:
Having awakened to Ultra Instinct for the third time, Goku starts fighting back against Jiren. In the bleachers, Whis notes that this latest appearance of Ultra Instinct is without a doubt their last chance; breaking through his limits to reach the level of the gods takes a heavy toll on Goku’s body, and he has no more allies or means of recovery left. While Goku’s movements have grown sharper than before, he is still unable to deal Jiren a decisive blow. This is the same problem he had earlier when battling Kafla: he can’t help but think while attacking, which interferes with Ultra Instinct.
To cope with this weakness, Goku adopts the same strategy as before, and charges up a Kamehameha as he draws closer to Jiren. Goku fires his blast at close range, but Jiren blocks it with a small hand-held ki blast, and counterattacks Goku. Toppo notes that Jiren has managed to get a handle on Goku’s movements and the depth of his power through their previous fight and by observing Goku’s battle with Kafla. Goku drops to the arena floor, but it turns out he avoided a direct hit by using the flow of his Kamehameha as a barrier.
Despite Goku’s persistence, Belmod remains unfazed: it doesn’t matter how good Goku’s defenses are if he can’t back it up with a solid offense. This incomplete Ultra Instinct is merely a delaying tactic, and Universe 11’s victory is still only a matter of time! However, Vegeta points out that calling it “incomplete” implies that there remains something even greater beyond it. The Saiyans have already broken through their limits repeatedly throughout the tournament, so it’s too soon to declare Goku’s defeat now.
Belmod seems disturbed by Vegeta’s words, and orders Jiren to ring Goku out immediately. Vegeta reminds Goku that he has entrusted him with his promise to Cabba and the others, and his pride as a Saiyan, so Goku can’t lose here. Goku pauses to breathe deeply before taking Jiren on again, and while at first it seems like he’s corrected himself, he still fails to turn the tables. While Tenshinhan and the others wonder if Goku is about to lose to Jiren as before, Whis assures everyone that there’s nothing to worry about: Goku is concentrating purely on the fight, his focus eliminating all worries, and his ki steadily rising.
Khai and Toppo are amazed that the heat radiating from Goku’s body is even reaching them out in the bleachers, and Belmod again urges Jiren to finish Goku off at once. Jiren responds by showering Goku with an incessant barrage of rapid-fire punches. Not only does Goku have his hands full blocking these countless blows, but the attacks are causing the ground beneath him to crumble away, meaning that at this rate he will drop out of bounds before too long. Piccolo and the others worry about Goku’s chances, but Beerus simply tells them to shut up and watch.
Though Belmod thinks that Beerus has resigned himself to fate, Toppo notices sparks as Goku’s fists begin to clash against Jiren’s; he’s switching from defense to offense! Soon Goku lands a powerful blow to Jiren’s chest, knocking him back. The Omni-Kings are amazed as Goku’s white-hot ki lights up the arena. Breathing deeply again, Goku gathers the ki around him into his body. Watching this, Jiren realizes that he must respond in kind, and powers up even further, giving off tremendous heat of his own. Jiren concentrates his ki into a single ball that he fires at Goku, but Goku appears behind him holding the ball in his hand.
Crushing the ki ball, the now shining Goku moves towards Jiren, dodging his punch and landing a few attacks of his own. The Omni-Kings continue to be impressed at Goku’s newfound power, and the Great Priest declares that this is indeed a super turn of events. Beerus and Whis can tell that, incredibly enough, Goku has managed to reach the completed version of Ultra Instinct. As Goku goes on knocking Jiren around with ease, the glow surrounding his body clears to reveal he now sports radiant silver hair and silver eyes.