Although Dragon Ball has teased Dragon Ball Daima actually disproves a compelling old-school theory about a major condition that had to be met before unlocking it. Though he would unlock more powerful forms in extended media, Vegeta didn't canonically have access to Super Saiyan 3 until Daima.

The theory initially arose to explain why Vegeta never transformed into a Super Saiyan 3 during the original Dragon Ball. The fact that each instance of Super Saiyan 3 was strange fueled further speculation. It was thought that the transformation could only be unlocked unconventionally or in an altered state of existence. As of Dragon Ball Daima episode #12, however that appears to no longer be the case.

Vegeta Achieves Super Saiyan 3 Under Normal Circumstances

Vegeta wasn't in an altered state, nor was he fused or dead

Before Vegeta, the only two Saiyans to achieve Super Saiyan 3 in official Dragon Ball canon were Goku and Gotenks. For Goku, he learned how to ascend beyond Super Saiyan 3 when he was dead on King Kai's planet. In fact, Goku was later surprised when he wasn't able to conjure enough power when fighting Kid Buu as Super Saiyan 3 and that was because he had never fought in that form for a long period of time while alive.

Most of what he knew about the transformation was based on his time in the afterlife. Meanwhile, Trunks and Goten never gained Super Saiyan 3 individually. It was only after they were in a fused state as Gotenks. In other words, fans believed that Vegeta could only reach Super Saiyan 3 when he was dead, fused or in some other altered state.

Dragon Ball Daima episode #12 seems to disprove this old-school theory when Vegeta transforms into Super Saiyan 3 when fighting the second Tamagami. If that battle had been the first time he achieved that form, then there could still have been a chance that the theory was still logistically sound, since he was in an altered state at the time. He was an adult who had been transformed into a kid. However, there are a few moments in episode #12 that disprove this.

Though a limited numbers of heroes have canonically unlocked Super Saiyan 3, a wide variety of Saiyans such as Nappa, Bardock, and Gohan have unlocked the form in officially licensed material that isn't considered canon.

The most obvious is that Vegeta isn't surprised or amazed when he transforms, alluding to the fact that he obviously unlocked Super Saiyan 3 before the fight, before reverting to a kid. Moreover, when Goku asks when Vegeta learned how to do it, Bulma says, "He's been training by himself for so long." So far, this is treated as fact. So Vegeta achieved Super Saiyan 3 under normal circumstances via training. He wasn't in an altered state, let alone fused or dead.

Did Dragon Ball Daima Create A Massive Plot Hole?

Or did Daima just prove that Vegeta is stronger than Goku?

Unfortunately, there are a number of reason this development might be seen as unappealing. For one, it serves as yet another example of Vegeta having to play catch-up with Goku. Daima might have further justified Vegeta's later obsession with suring Goku his own way rather than perpetually being in Goku's shadow, as evident during the events of Dragon Ball Super.

However, there are more than enough examples of Vegeta playing catch-up to warrant another. Additionally, the old-school theory for why Super Saiyan 3 is so rare gave the form a far more mystical quality, which was exemplified further by its rarity and the fact that it was more effective when the was dead.

However, a comment that a Yardrat later says about Vegeta in Dragon Ball Super proves that the Saiyan was even further behind Goku than fans initially thought, and this could have some interesting implications. When training on planet Yardrat, Vegeta is told in chapter #53 that his spirit - or chi - was even less stabilized than Goku's was when he first arrived there in Dragon Ball Z.

Since Daima takes place before Super, this means that Vegeta's chi hadn't been stabilized yet when he was fighting the second Tamagami. And yet, he was still able to become Super Saiyan 3, even though Goku only first transformed himself after getting his chi stabilized. Dragon Ball Daima either just created a plot hole or maybe now actually proves that Vegeta is just more capable than Goku, even though he is playing catch-up.