The next event roughly translates to “The Dragon that Governs the Sky”. In other words, it’s Rayquaza! During the event, you can recruit Zinnia (Higana in the Japanese version) and Rayquaza. There will be a special event mission that runs from 30th January till 14th of February. Kukui and Lycanroc can be Scouted starting the 30th as well. While Lycanroc is not a Legendary, it can be seen as a Pseudo-Legendary.
Later in February, there will also be a Steven & Metagross. He would have to be scouted, however. Again, Metagross is also considered to be a Pseudo-Legendary.
Rayquaza will be the third Legendary that will be added to Pokemon Masters. There is some controversy regarding their balance and their availability in the game. Some fans would rather not have any Legendaries when there are other more interesting pairs available that will not upset the power level of the game. Either way though, I’m sure a lot of fans are going to be excited for Rayquaza coming to Pokemon Masters.
You can visit the official Pokemon Masters website here.