Vegeta skipped Super Saiyan 3 and Super Saiyan God form?! What the hell is Super Saiyan God Super Saiyan / Super Saiyan Blue, anyways?
Worry not, derp Goku is here to explain everything to you.
Now lets begin with the basics and assume that Goku have a power level of 1000 in his base form to make things easy.
So this is Goku in his normal form at a power level of 1000:
Now what is a Super Saiyan? It’s basically a transformation which multiplies the power level of a normal form. It multiplies power by 50x, but lets assume that every form multiplies power by 10. So if Goku is at 1000 in his normal form, next comes Super Saiyan Goku with a power level of 10,000:
So far we clear? Good. Now this is where we move on the the next level. Next comes Super Saiyan 2, which will put Goku at a power level of 100,000. But what is Super Saiyan 2? It is NOT a new form. It is the same thing as Super Saiyan, but a more powered up version of it. To make it easy to understand let’s see this example:
Someone (Piccolo) just keeps on training in his normal form. With training he gets stronger and stronger. It’s the same thing. Goku kept training the Super Saiyan form and made it better and better thus, the result was Super Saiyan 2 putting Goku at a power level of 100,000:
Now comes Super Saiyan 3 which is exactly the same thing as Super Saiyan 2. The only difference is that it pushes the power of the person even further, therefore, Goku being 1000 in his normal form is 10,000 as Super Saiyan, 100,000 as Super Saiyan 2 and 1,000,000 as Super Saiyan 3:
This is where it gets complicated. We don’t see a Super Saiyan 4 after this but instead a Super Saiyan God.
SSG is something completely different from a Super Saiyan. To explain it to you in easy terms:
Normal -> SS1 -> SS2 -> SS3
Normal -> Super Saiyan God
Super Saiyan God doesn’t come after Super Saiyan 3 but rather it’s a completely different form. But what the hell is it? Now, in DBZ terms it’s a different type of ki compared to the normal ki. Let’s try to make sense of this in terms of other Anime. I hope you’ve seen atleast one of these two Anime I am gonna mention:
Normal Chakra | Sage Mode Chakra
Normal Chakra is Normal ki while Sage Mode Chakra is God ki.
Shinigami Powers | Hollow powers
Shikai is something like Super Saiyan 1 while Bankai is like Super Saiyan 2.
Hollow Mask Mode is a completely new form i.e. Super Saiyan God
And so, this Super Saiyan God transformation gives Goku a huge boost. Instead of a 10x multiplier, this transformation gives him something like a 100x or 1000x boost in one go. So a level 1000 Goku transforming in a Super Saiyan God will straight away reach a big power level such as 10,000,000 (10 times stronger than Super Saiyan 3):
At this point Goku can directly transform into a Super Saiyan God using the god ki and be more powerful than a Super Saiyan 3. This also explains why Vegeta skipped on Super Saiyan 3 transformation. It is because there is no need of going into a weaker Super Saiyan 3 form when he can already get much powerful than that to fight a stronger opponent. In human terms lets say instead of learning to punch 10x harder, Vegeta directly learned to punch 100x harder and faster. When he can do this there is no need for him to throw a weaker punch for such powerful opponents.
Now lets continue, next comes Super Saiyan God Super Saiyan / Super Saiyan Blue. Please, for the love of Super Saiyan God just call this thing Super Saiyan Blue.
Now remember how level 10,000 Super Saiyan Goku trained his SS1 form and the result was a Super Saiyan 2 with a power level of 100,000? Now Whis is smartass and instead of doing this what he wants Goku and Vegeta to do is to train their Normal self. So if Goku’s normal form trains and increases his power level to something say – 2000. Automatically the SS1 transformation will be a level 20,000 instead of 10,000. Training the base form will further improve the other forms when transformed. Now add to that fact that instead of using the normal ki, they start using god ki instead. God ki gives a HUGE boost (1000x by our assumptions) instead of 10x in one go. Thus, the training of Whis will make Goku and Vegeta learn to control their God ki and with the God ki a Super Saiyan transformation will result in the thing we call Super Saiyan Blue:
Pretty detailed stuff here for something so simple, well hopefully the Super Saiyan Blue is bit easier to understand now. Hasta la vista babes.