Dragon Ball Super's Galactic Patrol Prisoner arc has been compelling for many reasons, and two major reasons were the newest characters introduced into the series -- the new villain Planet Eater Moro and Merus of the Galactic Patrol. Both of these characters were pretty strong in their own ways, and both of them had dealt a pretty swift defeat to Goku and Vegeta on their first meeting. But since Merus was just a member of the patrol, he was the point of fan theories pretty early on that were settled with the latest chapter that revealed he was actually an angel hiding out in the mortal realm.
But why was he hiding out in the first place? As it turns out Merus initially joined the Galactic Patrol in order to understand the morality and virtue of the mortal realm, but got in so deep that he nearly broke one of the angel laws because he was planning to go and fight Moro himself.
Chapter 55 of the series sees Whis approach the Grand Priest about Merus. It's revealed that the Grand Priest is currently training Merus to be one of the Angels, but sent him to the mortal realm to get a better understanding of how things work (sort of like how Zamasu saw some of the mortal realm during the Future Trunks arc).
Grand Priest initially found nothing wrong with Merus in the patrol because he wasn't using his powers, but that was going to change with Moro. Just as Merus was preparing to train against Goku at full power, Whis arrives and reveals that he put at stop to things because Merus actually using his powers would constitute a fight. Even worse is that they couldn't allow him to go any further because he was planning to fight Moro himself.
Given that he already fought against Moro on Namek by trapping him within his patrol gear, Merus was most likely going to take this even further the second time around. But with Merus' plan discovered and him taken back to the angelic realm before the end of the chapter, now Goku and Vegeta will be left to their own devices as Planet Eater Moro heads towards Earth. But given that Merus was invested, will he back off so easily?
The Japanese-language and English dub releases of Dragon Ball Super are now complete and available to stream with FunimationNOW and Crunchyroll. Viz Media is releasing new chapters of the manga at a monthly rate that can be read entirely for free through the Shonen Jump digital library, and Dragon Ball Super's big movie, Dragon Ball Super: Broly, is now available on Blu-ray and DVD. Fans in Japan are also able to enjoy fresh non-canon adventures from the franchise with new episodes of Super Dragon Ball Heroes' promotional anime series.