The inevitable rematch between Son Goku and Black Goku in Dragon Ball Super is just a couple of weeks away, and if the recently-leaked episode titles are any indication, it would seem like the villain would be coming back with a vengeance.
As stated in previous episode title leaks, Black Goku would soon be unveiling his very own version of the Super Saiyan form, which is now officially known as Super Saiyan Rose. What is interesting, however, is just how powerful this particular and never-before-seen transformation would be.
Apart from the obvious hair color change, very little is currently known about Super Saiyan Rose. What could be deduced, however, is that it would be extremely powerful. So powerful, in fact, that it might very well exceed most of Son Goku's Super Saiyan transformations.
Immediately following the episode featuring Black Goku's Super Saiyan Rose transformation is an episode pertaining to Son Goku unleashing his Super Saiyan Blue form. With this said, it could be inferred that the villain's transformation would be too much for the Z fighter's conventional Super Saiyan forms.
Simply put, the only reason Son Goku would use his Super Saiyan Blue is if he had no other choice.
Considering that Black Goku is not an actual Saiyan, however, it is possible that Super Saiyan Rose is just a variation, or a corrupted version of Super Saiyan Blue. If this is indeed the case, Son Goku would definitely have his hands full on their upcoming rematch.
Then again, with Black Goku possibly being a Kaioshin, the notion of Super Saiyan Rose being more powerful than Super Saiyan Blue is also very plausible. In fact, with the progression of the plot in mind, it would make sense if Super Saiyan Rose would be presented as the most powerful transformation to date.
Prior to the start of the Future Trunks arc, Dragon Ball creator Akira Toriyama stated that the conflict in the storyline would ultimately involve the Omni-King himself. If Black Goku is a non-threat, the involvement of the universe's most powerful being would not make sense.
Thus, the few episodes of Dragon Ball Super might very well be the turning point of the Future Trunks arc -- the point where Black Goku becomes a very real, and very legitimate threat.