This Tretta was added to the prizes available to players taking part in the Ultimate Challenge starting with those held at participating Pokémon Centers and Pokémon Stores across Japan on October 3, 4, 10, 11, and 12, 2015. It was awarded again in the same manner at several later events. Details of these events are as follows:
- At Seven Town Azusawa, Itabashi, Tokyo on November 15, 2015.
- At Shopping Plaza Kamagaya, Chiba on November 23, 2015.
- At participating Namco arcades across Japan on November 28, December 6, 13, 19, and 20, 2015.
The Ultimate Challenge featured a team of Pokémon that appeared as Ultimate-class Tretta in the first three Pokémon Tretta Ultimate series sets: a Shiny Mega Rayquaza, a Kyurem, and an Arceus. While the opposing team was fixed for all events, the Arceus encountered could one of several types. Its Grass-type, Fire-type, and Water-type forms could be an opponent prior to the nationwide Pokémon Center and Pokémon Store events, expanding to include its Fighting-type, Steel-type, and Poison-type forms from those events. Players who managed to fill the Catch Gauge of any one Pokémon were awarded either this Tretta, a Rayquaza Tretta, or a Kyurem Tretta at random. Players who did not manage to defeat any Pokémon at these events were instead awarded either a White Kyurem, Black Kyurem, or one of two Mewtwo Tretta as a random consolation prize. The possible teams present at each Ultimate Challenge are detailed below.
