Summary
Toyotarou made significant changes to the Future Trunks arc, including the idea of Goku and Vegeta fusing into Vegito. Zamasu was originally weaker, but Toyotarou suggested making him stronger to make the story more interesting. Toyotarou played a major role in the development of the Future Trunks arc, demonstrating his impact on the story of Dragon Ball Super.
Dragon Ball Super It may be nominally written by Akira Toriyama, but the series' artist, Toyotarou, has actually had a surprising impact on the series in a way that most artists rarely do. In fact, Toyotarou is responsible for one of the series' most memorable moments, from the Future Trunks arc.
The Future Trunks arc of Dragon Ball Super revolves around the mysterious appearance of a figure who looks exactly like Goku, but his actions are so evil that it becomes clear that he is definitely not Goku. Dubbed Goku Black, he begins to destroy Future Trunks' world, and it is eventually revealed that Goku Black is actually a Kai-in-training from Universe 10, Zamasu, who has stolen Goku's body. Zamasu's goal is to purge the universe of mortals, in order to create a perfect world free of the savagery that mortals exhibit.
With godlike power at their side, Zamasu and Goku Black pose an incredible threat not only to Future Trunks' world, but to the greater universe as well.
The Best Moment of the Future Trunks Arc Was Toyotarou's Idea
The original Zamasu was defeated without fusing.
In an interview from Dragon Ball Super episode 4, translated by fan site Kanzenshuu, Toriyama and Toyotarou were asked about any difficult points while writing the Future Trunks arc. Toyotarou explained, “[Merged] Zamasu was actually not a strong character in the original manuscript I received from Toriyama-sensei.. Despite being immortal, his power is so great that two Super Saiyan Blues are more than enough to defeat him. That's why in the original draft, everything went in the direction of his “immortality” and “Potara time limit” becoming the key, and Goku and Vegeta took turns fighting him. Goku and Vegeta were not fused in the original draft.”
Being a fan himself, Toyotarou wanted to deliver what the fans wanted to see, and suggested that Zamasu be much stronger – so strong that it would essentially force Goku and Vegeta to fuse into Vegito for the first time since the Buu saga. Toriyama was in favor of the changes, and so Toyotarou elaborated on the scenes surrounding Merged Zamasu, finally giving fans the version they know today. Goku and Vegeta fusing again was certainly an exciting moment, and what better enemy to force such a fusion against than someone who is practically an immortal god?
The original version, as Toyotarou describes it, would certainly be less exciting than seeing Vegito again, and it fits so naturally into the story, with its connection to the Potara Earrings, that it's hard to imagine a complete version without seeing the Saiyan pair fused. If this is the kind of story Toyotarou was telling based on Akira Toriyama's original, then it seems like Toyotarou has become a key figure in the development of the story even at this relatively early stage in the manga. With Toriyama gone and someone needing to take up the torch, Toyotarou seems ready to take over. Dragon Ball Super.