Atlus released a new trailer for Persona 5 Royal that showcased Ryuji Sakamoto and revealed that the party members can receive a third Persona in the game.
In Persona 5, Joker is a "Wild Card," which means that he can own multiple Personas at once, but can only use one of them at a time. The other Phantom Thieves are limited to only a single Persona each, but if the player maxes out their Confidant rank, then the Persona will evolve. In the case of Ryuji, he starts out with a Persona called Captain Kidd, which can evolve into Seiten Taisei.
The latest trailer for Persona 5 Royal shows Ryuji's two Personas fusing together into a new one, which is called William and resembles Captain Kidd, except with elements of Ryuji's design added to it. The William name is likely a reference to Captain Kidd's real first name.
It's likely that the other members of the Phantom Thieves will also receive a third Persona each, as it seems unlikely that a new mechanic would be created just for Ryuji (as much as we love him). The other third Personas will likely be revealed in the upcoming character trailers that will be shown in the run-up to the Japanese release of the game.
The Ryuji trailer also shows off one of the new team attacks in the game that he can perform with Yusuke. Ryuji is shown in a bar with Yusuke, who cooks a special meal for him. A monster bursts in through the door of the bar and both Ryuji and Yusuke turn and fill the monster full of lead. Ryuji tosses a grenade, which Yusuke shoots and causes it to explode.
Ryuji is Joker's first ally in Persona 5 and is one of the founding members of the Phantom Thieves. His role in the story of Persona 5 Royal likely won't change too much, so it makes sense to reveal some of the new features in the game in his character trailer.
Persona 5 Royal will be released for the PlayStation 4 in Japan on October 31, 2019, and internationally in 2020.