Dragon Ball Super has been opening up its multiverse with the Galactic Patrol Prisoner arc, and one of the more interesting additions to the series in the midst of all of this expanding lore has been Merus. This Galactic Patrol member made a huge impact almost immediately when he took down Goku and Vegeta with ease upon their first meeting, and sparked even more fan theories when he began training Goku to better harness his Ultra Instinct abilities. But those theories were put to rest in the latest chapter where it was outright confirmed that he was an Angel in training.
But the latest chapter of the series also cemented the Angel laws in place as it revealed that these all-powerful beings too have laws and decrees that keep them in line. Because Merus was in danger of breaking these laws and nearly was "eradicated," he unfortunately had to say goodbye in Chapter 55 as he heads back to the Angel realm with no signs of return.
Chapter 55 of the series reveals that the Grand Priest had been watching over Merus all this time. Merus is his angel trainee that he dispatched to the mortal realm in order to broaden his perspective, but the one law that Angels must follow is impartiality. They have free range to pretty much do whatever they want, and Grand Priest allowed Merus to join the Galactic Patrol as it seemed like he did it to learn about virtue, but has since developed a bias.
Since he's pushing the limit of what he can get away with, the Grand Priest decides to Merus' time in the mortal realm or else he'd have to erase him completely. Thankfully, Whis argues to bring Merus back rather than full on erasure because Merus had yet to use his Angel abilities in battle. So this means that Merus is being taken to the Angel realm for the time being, and it's goodbye considering that he may never come back to the mortal realm let alone Universe 7.
There's no sign of him coming back just yet, but as he's a rookie angel in training, there's still hope that he can appear again in the future. But since he's in Whis' care for now, this could mean he'll pop in here and there but won't be involving himself in any significant way lest he actually break one of these major laws.
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.