"Protect Supreme Kai Gowasu - Destroy Zamasu!" (界王神ゴワスを守れ ザマスを破壊せよ！, Kaiōshin Gowasu o Mamore – Zamasu o Hakaise yo!) is the 59th episode of Dragon Ball Super. Its Japanese air date is September 25, 2016.
Goku, Beerus, Whis, and Shin visit the Sacred World of the Kai in Universe 10, asking Gowasu where Zamasu is. Zamasu, bringing Gowasu's tea, politely welcomes the Universe 7 group while wondering to himself why they are here. While Zamasu is brewing Gowasu's tea, Gowasu tells him that they are here to see him. Beerus and Whis tell Zamasu that they returned because Goku wanted to fight him again, but before Goku can say he doesn't recall asking about that, Beerus hits him and tells him to be quiet. Zamasu thinks to himself for a bit then calmly accepts Goku's challenge, claiming he was also unsatisfied with how long their last match ended. Beerus then dismisses the fight while Whis says they must go, as it is time for Beerus' afternoon nap. Whis presents Gowasu a gift: some Great Fortune snacks and some freshly-brewed green tea from Earth. The Universe 7 group leave, but not far from Universe 10, they stop and Whis forms a barrier. Shin asks how it went, and Whis and Beerus confirm that Zamasu is planning to kill Gowasu, noticing his extreme killing intent. Whis jokingly says Zamasu's killing intent is about as pungent as one of Beerus' farts, prompting the God of Destruction to berate him. Goku says he did not notice anything off about Zamasu's spirit, and Whis says that as the God of Destruction, it's only natural for Beerus to notice, along with Whis. Shin also did not notice, realizing that Gowasu does not notice, either. Goku suggests that they go back and help, but Beerus and Whis dismisses him, saying that they will not until they find some physical evidence. Whis creates a projected view of Gowasu and Zamasu and the group sit back and watch as Zamasu pours Gowasu some of the green tea. Gowasu drinks the tea, commenting that it calms the heart.
Meanwhile, in the alternate timeline, at a safe house, Goku Black and Future Zamasu discuss about killing Goku and how they aren't strong enough as opponents. Future Zamasu says if Goku Black kills Goku too quickly, he'd lose an opportunity to grow stronger by adapting to his fighting style, suggesting that he kills Goku slowly and carefully. Future Zamasu asks if it is nice to have immortal bodies due to the Super Dragon Balls. As a response, Goku Black turns into Super Saiyan Rose, and claims he is satisfied with this power and unlimited potential, which is necessary for their plan. Future Zamasu says it is ironic that they are using a "mortal" to go through with their plan to exterminate all mortals. At the Earth's Resistance base, Future Mai looks at the weakened civilians and soldiers and wonders how much longer they will hold out. Haru & Maki approach Future Mai with dumplings, saying they got them from Future Yajirobe. Despite Future Mai claiming she is fine, she is persuaded to eat one with the kids. Future Mai thinks to herself that even if by herself, she must protect their smiles.
In the present timeline, at Capsule Corporation, Bulma is repairing the time machine's transfer device, Vegeta is training in the Gravity Room, and Future Trunks is sitting outside sulking, thinking about how he ran away without Future Mai, again. Pilaf, Mai and Shu, who are watching him from behind a bush, worry about him, and the two boys suggest that Mai go cheer him up. When Pilaf and Shu jokingly act like Mai confessing her love for Future Trunks, Mai angrily yells at them to leave. Trunks, also watching his future counterpart, approaches him. Trunks berates him for moping around after one loss. Future Trunks politely asks Trunks to leave him alone, prompting Trunks to call Future Trunks a coward and he is unable to protect Future Mai that way. Trunks then asks him if he is mad, and challenges him to a fight, turning into a Super Saiyan. When Future Trunks does not move, Trunks agrees to make the first move and punches Future Trunks in the face, knocking him down. Trunks yells at Future Trunks to stand up, since he "is supposed to be a Saiyan" while Future Trunks glares at him.
Back in Universe 10, Gowasu claims the Universe 7 food is delicious and suggests Zamasu to try some, while Zamasu declines. The Universe 7 group notice Zamasu not taking any action at all, and Goku says he is growing hungry watching Gowasu eat. Whis tells him to be a little more patient. Zamasu walks behind Gowasu and begins to talk to him about his perspective over good and evil, and Gowasu says that he will one day understand what Gowasu means. When Gowasu takes another bite of the Great Fortune, Zamasu prepares his God Split Cut energy blade, intending to kill him. Gowasu flinches, but it is shown that he choked on the Great Fortune, and washes it down with tea. Zamasu charges his attack again and successfully kills Gowasu. Whis then performs his Temporal Do-Over, going back in time to before Zamasu kills Gowasu. Whis suggests that they do this again, while Goku is confused, but realizes they went back in time. With the proper evidence, the group returns to Universe 10. Before Zamasu kills Gowasu, Whis creates a strong glove around Zamasu's hand to block the attack, shocking the apprentice. Gowasu wonders if that glove is a new item for tapping shoulders, while Zamasu is flustered and notices that the Universe 7 group has returned. Beerus explains to Gowasu that Zamasu tried to kill him, with Whis proving this by removing the glove, revealing Zamasu's energy blade. Gowasu, shocked, orders Zamasu to explain himself. While Zamasu remained silent, Shin explained Zamasu's plan to get rid of Gowasu, steal the Time Ring, use the Super Dragon Balls to create a fake Goku and wish for immortality, and exterminate all humanity. Zamasu is surprised they know this, and Goku says that they learned everything from going to the future. Zamasu then proclaims that he cannot fall in a place like this and prepares to attack, with Goku taking a fighting stance, but his attack is easily caught by Beerus. Telling him not to get too cocky, Beerus raises his hand in front of Zamasu, and says "Destroy", disintegrating Zamasu's entire body, killing him.
Back on Earth, Future Trunks and Trunks have been fighting, and Future Trunks realizes what Trunks is trying to teach him: win, no matter who the enemy is. Future Trunks thanks his younger self while shaking his hand, when Goku and Beerus suddenly crash in-between them with Whis; Goku commenting that they should have asked Shin to take them back. Beerus tells Future Trunks about Zamasu's death, and with that the future is saved as Goku Black should also disappear. Future Trunks asks if the future is really saved, as the Androids in his timeline did not disappear after the ones in the present were defeated. Beerus says that it is different if a God eliminated another God. Bulma says that it is no laughing matter if nothing in the future changed. Future Trunks says he hopes the future is now safe.
- This is the first time Future Trunks sees his past self as a Super Saiyan.
- This is the second time Whis uses the Temporal Do-Over technique.