Team Rainbow Rocket

Team Rainbow Rocket, also called Team RR, are major antagonists in Pokémon Ultra Sun and Ultra Moon, serving as the main antagonists of the post game story "Episode RR". They are a reincarnation of Team Rocket, lead by and composed of the Pokémon franchise's past villains, who plot to take over different alternate universes using Ultra Wormhole technology.

Trying to Take Over Festival Plaza
In the prologue to "Episode RR", Team Rainbow Rocket's grunts invade Festival Plaza, hacking the virtual world and redesigning the castle to sport a more sinister design. After this happens, Sophocles rushes over to the player's house, and alerts them to the invasion that has taken place. When Sophocles and the player enter the castle, they encounter a group of grunts, one of which proclaiming the castle now belongs to them. Sophocles realizes that the Plaza has been patches so that nobody can use their Pokémon while inside, although, while looking for a new solution, one of the grunts accidentally lets it slip that the player can use other people's Pokémon while in the Battle Agency. Sophocles reactivates the Agency, and, while the player battles one of the grunts, he hacks into the Plaza and restores his admin privileges. Upon returning, the grunts attempt to assault the player and Sophocles, but the latter bans them from Festival Plaza immediately (although the castle keeps its new design).

Trivia

 * All Rainbow Rocket Grunts that can be fought during Episode RR only use Pokémon from the Kanto region.
 * Team Rainbow Rocket is the only major antagonistic organization from the games that has yet to make an appearance in the anime or manga series'.