I have just finished watching "The Legendary Super Saiya-jin" , and a few things stike me as strange with Brolli's transformations.
After reading the page outlining Brolli's tranformations from his normal stage, to SSJ and his "legendary" stage, I personally believe that there is no "legendary" stage to speak of. Part of this theory stems from a couple of scenes, where Brolli is in outer space with his father.
He seems to be surrounded by a pinkish aura, and his hair does not seem to be green as noted in his "green-haired" SSJ transformation, rather it is reflecting the pink aura , so I'm assuming it's actually gold and that he is in his regular SSJ stage, just like a regular SSJ (Goku, Vegeta etc). I belive only after he was brought under control, his power was limited, which only allowed him to become a "half-powered" ssj, which we see in pictures and the movie. If his hair changes from black - to green - to gold, that would makes sense....
As for his legendary form , i believe that it is only his prefered form. Notice that in the Cell Saga. Goku perfects the SSJ form after training with Gohan in the Spirit and Time room. This allows Goku to take Cell on as an equal, even after both Trunks and Vegeta tried to defeat him in USSJ and USSJ2 forms. So, in this case, a "regular perfected" SSJ is more powerful than the "imperfected" higher stages of SSJ.
I would think that Brolli just prefered to use this form , and over time he eventually got used to it and was able to stay in the form and increase his speed and power. I think that the form we assume to be the "legendary" form is only the perfected USSJ3 form , which we never see any of the other Saiya-jins reach.
I'm sure that if any of the other Saiya-jins stayed in a "prefered" stage, they would grow used to it and perhaps overcome the downsides of using the form, such as the Goku vs Cell scenario.
There is a lot of assuming here , but this is just my opinion
Sorry for the long post, but thoughts on the matter would be great!
Cheers,
ItsAllGood



