From Bulbanews, your community Pokémon newspaper.
Each team must include Diancie
Details for the Diamond Storm tournament have been announced. Each team will contain Diancie. Each participant that records a battle will be able to receive 1,000 Poké Miles and be included in the rankings. This tournament is only known to be open to Japan.
Players may register between 2 p.m. JST on Sept. 4 and 8:59 a.m. JST on Sept. 12. The tournament will be held from 9:00 a.m. JST on Sept. 12 until 8:59 a.m. on Sept. 15. The rankings will be revealed on Sept. 19. Participants born in or after 1999 will be in the Junior Division. Participants born in or before 1998 will be in the Masters Division. Players in the Junior Division will not be able to participate between 11 p.m. and 6 a.m. JST.
50,000 players may be able to participate, on a first-come first-serve basis. The competition is Single Battles, and only Pokémon in the three Kalos Pokédexes may compete alongside Diancie. Mewtwo, Yveltal, Xerneas, and Zygarde may not be used. Each battle will be 30 minutes. Players will have 90 seconds to decide which Pokémon to battle with and one minute to decide what to do each turn. Players may only battle 10 times per day, for a total of 30. Pokémon must be registered in the Battle Box on the PC and they will be set to level 50 for the tournament.