Super Saiyan 3 Goku was no weakling after the Cell Saga.
The first time we actually saw Super Saiyan 3 Goku was in Dragon Ball Manga chapter 474.
Chapter474 also correlates with Dragon Ball Z Aime Episode 245.
That is when Goku was facing off against Majin Buu and realizes that Super Saiyan 2 is not going to cut it against Buu.
Majin Buu was too powerful and thus Goku showed everyone that he could even go further Beyond

Goku just rips in the Western Capital and shows his great power against Buu in Super Saiyan 3.
So, we find out in the Dragon Ball guidebooks that Super Saiyan 3 is multiplier is a four times multiplier from Super Saiyan 2.
This equates to a 400 times multiplier base form. Keep in mind that Goku also trained his entire body hard during the seven-year skip.
So this base from Goku is much stronger than any base form that we’ve ever seen before.
The big thing about Super Saiyan 3 is entirely like a machine. That form is built for combat and built for eliminating your opponent as quickly as possible.
Goku Super Saiyan 3
There is a lot of energy consumption in the Super Saiyan 3 form, possibly more than any other transformation in the entire series.
It increases your speed and your power significantly.
However, it also has a huge handicap and that is the strain on the user.
This is shown several times in the series when Goku first turned Super Saiyan 3 to matchup against Majin Buu.
Goku vs fat Majin Buu
Goku did indeed get a lot of really good hits on Buu but was unable to finish him off.
The reason for that is because Goku using just Super Saiyan 3 in his fight which was not him at full power used up so much energy.
That energy was enough to actually drown the 24-hour period that Goku had on Earth to come back to life for one day.
For those who don’t know who did not know Baba the witch on a floating ball has the ability to bring you back to life for one day.
SSJ 3 Goku Dragon Ball Z
Super Saiyan 3 puts out so much energy that Goku actually eliminated several hours from his time back on Earth.
This was because of how much energy he put out.
Later on in Dragon Ball Z when we see Gotenks fighting Buu, we find out that the fusion plus Super Saiyan 3 put out so much energy that it greatly reduced the time that they were fused together before they defused.
So it was believed that Super Saiyan 3 is a form that really can only work to its best potential in the afterlife.
That’s what many believe and the reason for that is not just the examples that pointed it out.
Majin Buu Vs. SSJ 3 Goku
Later on, in Dragon Ball Z during the fight with Kid Buu, Goku was so overconfident with Super Saiyan 3.
He thought that if he could hit the full complete power of Super Saiyan 3 he could kill Kid Buu.
So when he tried to do it his body would not allow him to hit the transformation.
However, what happened is that he burned out and he went back down to his base form.
He used up way too much energy which is why I Goku could not beat fat Buu because there was no way for him to have done it.
If Goku went full power to beat fat Buu, he would have completely drained his time on earth and would have to go back to the afterlife.
However, if he was alive it would burn out his entire body.
So the way that Super Saiyan 3 should be looked at in Dragon Ball Z is that it was an experimental transformation.
Even though we don’t have exact dates are times too when it happened.
One could easily deduce that Goku discovered Super Saiyan 3 not too long before he came back to life.
It’s possible that he did not have enough time to perfect it and as a result of that, he could not contain the power for a long.
The Power Of Super Saiyan 3
Super Saiyan 3 is meant to be a form you use to fight quickly because the more fight goes on and the stronger your opponent is the more energy you will drain.
That’s just how Super Saiyan 3 Goku works.
Unfortunately, somebody like Buu can regenerate over and over again and has more stamina than just about anybody.
Super Saiyan 3 is just not going to work because of that huge handicap.
That being said, one thing that I’ve always thought of is how does Super Saiyan 3 form Z match up to Sper?

What I mean by that is when Goku face-off against Lord Beerus in Battle of Gods the movie, anime and in manga as well.
Goku got smashed? I mean it wasn’t even a contest but I wonder if by that time since Battle of God took place, for years after the death of Kid Buu.
I wonder if by then Goku has finally figured out how to master Super Saiyan 3? I’ve always believed that it was the case because I feel like four years is plenty of time for Goku to really figure this out.
However, during the Buu saga, the stamina drain was still a problem for Goku and energy consumption.
Without energy, you can’t do anything and unfortunately, that’s what this form problem is.
However, Super Saiyan 3 still looks cool and it gave us some great moments like of course the dragon fist from Dragon Ball Z movie 13.
So as far as combat goes that handicap is not going to work against somebody like Majin Buu.
Gotenks Super Saiyan 3
The second person that we see doing Super Saiyan 3 was Gotenks.
We see that in Manga chapter 493 of Ball Z episode 260 and in the animated version.
Goten and Trunks were able to actually witness Goku doing Super Saiyan 3.
I presume that with their training and their potential and the magic of the Metamora fusion pose.
Gotenks was able to figure out Super Saiyan 3 at 1 combine being as opposed to just Goten and Trunks being individuals.
This as been a bit of debate amongst fans for years as far as the quality of the series goes.
It feels like Super Saiyan 3 Gotenks was something Toriyama just last-minute decided to throw in there without any sort of buildup.
There really is no build-up to this but the same could be said for Super Saiyan 3 when Goku did it.
In fact, there are manga chapters where Goku tells everybody that he did his best against Majin Vegeta.
Toriyama Reckoning SSJ3 Form
Some have taken that as Toriyama Reckoning it to where he was hiding Super Saiyan 3 because of the energy consumption.
Also that he didn’t want to make Vegeta feel bad or whatever the case is.
However, this logically just tells me that Toriyama had not really come up with this transformation yet.
I guess he was not really sure how he’s going to come about doing it but of course, we do have early designs of it.
So he had to change his mind at some point, we just don’t have exact detail as to when that is.
Nonetheless, Gotenks shows that he’s very powerful as Super Saiyan 3 in Dragon Ball Z. But again he killed the fusion.
Even though they did not know about the handicap of this form. However, we are dealing with kids here.
So obviously they won’t know things like that, Goku was able to figure out on his own even though Goku himself was overconfident.
So Goku wound up burning himself out just a little while after during the fight with Kid Buu.