Vegeta becomes a Super Saiyan God Super Saiyan (Super Saiyan Blue) in the movie Resurrection F. How did he become a Super Saiyan God?
Was the ritual performed on him before the Resurrection F event or did he use his own power to become a God? (That's what he tells on one of the Dragon Ball Super episodes)
After reading over the Wikia article on Vegeta, it seems there is not a clear answer on how he gained his Super Saiyan God form.
Since Dragon Ball Super is canon, if in the episode Vegeta said that he obtained the form on his own I would assume that he is not lying about it.
In the Wiki, it is said that Vegeta went and trained with Whis for six months before Goku came to join him. It is most likely it was during this time that he obtained the Super Saiyan God form.
After later gives Whis Ramen and he finds it delicious. He takes Vegeta in as his student and takes him to Beerus' planet to train him for six months. After six months has passed, he is waiting for Whis return from Earth. Whis has Goku along with him. Goku notes that Vegeta has gotten stronger and he may have surpassed him.
The Wikia page states that:
Super Saiyan God Super Saiyan, also known as Super Saiyan Blue, is the result of a Saiyan transforming into a Super Saiyan after absorbing and retaining the power of Super Saiyan God and training.
That is, that to achieve SSGSS, one must achieve and master SSG first.
However, as it wasn't done before Vegeta went off to train under Whis, the only options left are that either he performed the ritual on that planet, or his training with Whis helped him do so. The SSG form is just another Saiyan transformation, the only thing being different is that instead of normal Ki, there is divine Ki flowing through your body and you can even perceive it now. As a result, you can even absorb energy attacks. As Vegeta said that he mastered the SSG form, I would believe it and would further add that by mastering the form he said that he mastered the perception and usage of the divine Ki, thus making it flow through his body evenly and unlocking the SSGSS form.
There is reference to this in the anime when he senses the return of Whis (watch here), and later the oracle fish comments that he's finally able to sense divine Ki. Goku even states that Vegeta's Ki had changed a lot during the six months he had spent training under Whis (watch here).
It's similar to that incident when Goku and Gohan had unlocked the Full Power Super Saiyan transformation after training in the hyperbolic time chamber in the cell saga. The FPSSJ transformation was the mastering of SSJ1 and making it the base form, thus reducing the strain on the body and making it easier to raise power levels. What they managed to do can be thought of controlling the SSJ1 Ki and making it flow evenly through their bodies, thus mastering the form.
The training both Goku and Vegeta are undergoing, which deals with raising power levels, a manifestation of Ki, without letting it leak, or, in other words, letting the opponent know, making each part of the body capable of independent action and also the perception and mastery of divine Ki, thus mastering SSG, SBG (Saiyan Beyond God) and SSB transformation.
After Goku arrived on Whis's planet, Vegeta and Goku had sparring training, while having hand to hand combat in an attempt to control their Ki. They somewhat triggered a blue aura which Whis pointed out in his mind as God Aura, right now Whis has thrown them in another dimension which is more like the Hyperbolic Time Chamber. I guess that place would grant them the key to attain SSGSS form. Do follow the DBZ Super manga for some story ahead.
If vegeta had not obtained this form before Goku got to beerus planet then I can only assume that when goku and vegeta were sparring and they triggered the blue aura , vegeta must have absorbed some of Gokus god ki, then when they were thrown into the other dimension by Whis vegeta must have transformed hence how Goku knows how Vegeta transformed.
Vegeta gained the Super Saiyan God power the same moment as Goku during Battle of Gods. If you pay attention during Dragonball Super while Goku and Lord Beerus are fighting in the outter atmosphere, Vegeta is clearly following the fight standing on the ship while everyone else is freaking out. Piccolo even notices it I believe. I don't know what episode, but it's on the show. Vegeta was able to follow the fight by being able to sense the God power. He had every credit to become the God himself in the original situation but Goku wanted the fight. Vegeta was the only other full blooded Saiyan known left in the anime during Goku's power up. Therefore giving him also the gift to sense/control the divine power.
The Wiki never quite answers it, however several inferences can be made from the Anime (since the Manga for DBS is based on the Anime, not the other way around):
When Vegeta first fights Beerus and Bulma is slapped, Vegeta then gains a massive power boost, and fights Beerus off very successfully for some time. What this tells us is that Vegeta himself has the capacity for the sheer amount of power of the SSG form.
While Beerus is fighting with SSG Son Goku, we notice Vegeta closely watching, and as the fight goes on, he seems to almost be able to sense Goku's godly ki. This is the main inference: He has spent so long fighting and training with Goku, that he knows his ki almost as well as his own. As he watches SSG Son Goku, I postulate that he is in fact beginning to sense Son's godly ki, and training himself to be able to not only sense it, but eventually replicate its godly nature.
He trains for around 6 months with Whis, and during this time, he seems to increase his power enough to generate the SSG form himself. We know he has the capacity to, from points 1 and 2, and so, this explains his godhood. Under his own power, and not relying on the charity of the other Saiyans.
This is how I see it happening, after watching the Anime several times in an attempt to understand this.
Hope this Helps!
According to http://dragonball.wikia.com/wiki/Super_Saiyan_Blue
Super saiyan blue is an advanced level of the Super Saiyan form that uses controlled godly ki. This form can be accessed after absorbing the power of a god and then combining it with the Super Saiyan form or through vigorous ki control training.
Vegeta attains controlled godly ki when he is sent to another dimension along with Goku by Whis. There he says "I get it. If I control my ki so it doesnt leak after having raised it, I can move. Is this what they call God Ki?"
So in the other dimension Vegeta learned how to use god ki. Some time after he combined that god ki with the super saiyan tranformation and became Super Saiyan Blue. He didnt need to become super saiyan god to be able to transform into super saiyan blue, he needed to use controlled godly ki which he adquired by training in that other dimension and combine it with the super saiyan transformation
Maybe the reason that they are linked is because when they fuzed with the potara earrings. They became one being and then separated and were still one. There is a reason that Vegeta never wants to fuze with Goku and I think they share everything, memory's, power, ect....
I think, if I understand correctly, that by training with Whis, he absorbed some of his ki. Like, by training to learn ki control with a deity, he could obtain some of his power. That's what I understand from the wiki.
Let's get one thing straight. Saiyan God (Red) and Super Saiyan God (Blue) are two separate transformations. Vegeta skipped the red hair form and went straight to Blue. How he did this is simple. He learned how to use Godly Ki while training with Whis. He then used that God Ki with his Super Saiyan form, thus making him a Super Saiyan God Super Saiyan (SSGSS / Super Saiyan Blue / SSB)
