With the appearance of Black Goku and his transformation to Super Saiyan Rose in "Dragon Ball Super" Episode 56, not to mention the arrival of Zamasu on the scene, fans are undoubtedly looking forward to how the story will unfold in Episode 57. There are various predictions and speculations, including the revelation of the relationship between the god apprentice and the evil Goku.
Previously, Son Goku's team had been trying to figure out who Black is. They surmised it to be Zamasu because of his ki, but they tossed the idea out anyway. When Bulma finally fixed the time machine, Goku and Vegeta accompanied Trunks back to the future where they met the resistance and Black.
In Episode 56, Vegeta, in his Super Saiyan Blue transformation, faced off with Black, who showed off his Super Saiyan Rose form. As they were fighting, Trunks again brought up the possibility of Black being a god, specifically Zamasu.
Vegeta fell when he was stabbed by Black's aura-like blade, so Goku faced his look-alike, also in his Super Saiyan Blue form. The protagonist lost and was about to be on the receiving end of a Kamehameha when a voice stopped Black. Zamasu was then shown descending from the sky, and he and Black stood side by side, facing the Saiyan team.
"Dragon Ball Super" Episode 57 is titled "God with the Invulnerable Body - Zamasu's Advent." Taking a hint from that, the episode just might reveal what happened to Zamasu after his conversation with Gowasu over tea when he killed a Babari - about ending evil by eradicating humans versus the balance between good and evil.
Zamasu may have done something behind Gowasu's back, possibly giving life to Black using his ki and it might reveal how Black got to wear a Time Ring and a Potara earring. It could also be that Black and Zamasu would fuse in Episode 58 using their earrings, giving birth to a virtually indestructible Zamasu.
These are just speculations, of course, but fans can expect more revelations in "Dragon Ball Super" Episode 58, which is titled "The Mystery of Black and Zamasu," according to Yibada. One question, though, is why Black gloated about mastering Goku's powers. An idea is that he either has Future Goku's body or he is Future Goku.
In Episode 57, Goku will be facing off against Zamasu while Trunks will be joining the fight. How they will win against their formidable foes remains a mystery for now, but it can be speculated that Zeno's gift to Goku - the little gadget with a button - just might become useful.