Dragon Ball Super has confirmed the godly source of Uub's power in the newest chapter. When Dragon Ball Z came to an end years ago, fans were introduced to a young boy who was the reincarnation of Majin Buu, Uub. It was revealed that this young boy had a well of power inherited from the evil Buu incarnation following its defeat at the hand of Goku, and it sparked a ton of fun theories when Uub was reintroduced to the franchise as part of the Galactic Patrol Prisoner arc. Now one of those major theories has been confirmed.
The newest chapter of the series officially brought the fight with Planet Eater Moro to an end, but it was a much messier end for Goku and the others than initially anticipated. When Goku needed one final bit of energy to reach his Ultra Instinct form once more, he ended up getting a major boost from Uub -- who was confirmed to have inherited god ki from the evil side of Majin Buu.
One of the major reveals from early on in the Galactic Patrol Prisoner arc is that when Buu's evil side had separated from his good side, the evil side had in fact all of the god ki that it had absorbed from eating the Grand Supreme Kai. After this reveal, fans had suspected that Uub had god ki as well and that it would explain his immense power (and Goku's interest in him) towards the end of Dragon Ball Z.
This ends up being confirmed in Chapter 66 of the series. Because when Uub sends a mass of god energy toward Goku, Dende and Jaco piece together that Uub had reincarnated with the divine power once stolen from the Grand Supreme Kai. It was the Kai who had approached Uub for his last minute help as well, and definitely adds another interesting layer to Uub overall.
This reveal further fleshes out Uub's importance in the series, and helps to add another layer to why Goku would drop everything to train him. Because if Uub indeed has divine power like Goku's, the Saiyan must have been intrigued by finally meeting someone who could have divine power comparable to his own. But what do you think of seeing Uub confirmed to have divine power? Let us know your thoughts in the comments or you can even reach out to me directly about all things animated and other cool stuff @Valdezology on Twitter!