WARNING: The following contains spoilers for Dragon Ball Super Chapter 71, by Akira Toriyama, Toyotarou, Caleb Cook and Brandon Bovia, available now in English from Viz Media.
Since its introduction, Ultra Instinct has remained something of an elusive target for Goku. While the Saiyan was finally able to readily access the ability with help from the Angel Merus, the Saiyan hero's fight with Moro almost ended in tragedy due to the sheer amount of power using Ultra Instinct takes. However, as Whis reveals in Dragon Ball Super Chapter 71, the only reason Ultra Instinct consumes a lot of Goku's power is because he's using it wrong.
At the start of Dragon Ball Super Chapter 71, Whis asks Goku if he knows the difference between himself and the Angels. The Saiyan -- who has never prided himself on his intellectual gifts -- remarks that it must be the halo around Whis' neck. This response causes the Angel to summon his staff and smack Goku on the head. After this harsh lesson, Whis says, "It's that we are always in the Ultra Instinct state."
While Goku tries to reply that he must transform to use Ultra Instinct, Whis corrects him, saying, "Not exactly... It's that you're equating Ultra Instinct to a transformation. When your heart is calm, your body should move on its own no matter what form you're in." From here, Whis demonstrates his ability to use Ultra Instinct and impresses Goku, who vows to learn how to use Ultra Instinct not as a power-up. If he's able to accomplish this feat, as Whis says, Goku will be freed from the "stamina drain" that impeded him during the fight with Moro. However, Whis does hint that there's a power of some sort transformation that accompanies Ultra Instinct, though it's a last resort.
For pretty much the rest of Dragon Ball Super Chapter 71, Goku trains to better use Ultra Instinct and seems to proceed quite far in his training. However, he's never shown in a straight-up battle situation, making it unclear just how much he's internalized during the chapter's short, unspecified timeskip. Still, Whis' big reveal that Ultra Instinct isn't a transformation will heavily alter how Goku uses the ability in the future.
This twist makes some sense, and the hints that Ultra Instinct isn't a true transformation have been around all along. During the "Universe Survival Saga," Master Roshi was able to use a very unrefined approximation of Ultra Instinct. However, there was no indication at the time that Roshi was undergoing any sort of abnormal transformation. As such, it makes a lot of sense that Ultra Instinct is more of a state of being than a true transformation. And now that Goku is learning how to use Ultra Instinct properly, he may just become a more formidable threat than ever before -- especially if he discovers the last resort transformation of which Whis made mention.
Dragon Ball Super Chapter 72 releases May 20.