From Bulbanews, your community Pokémon newspaper.
Pokémon with five weaknesses or more are only allowed
The Weakness Cup Wi-Fi competition has been announced. This competition will use the Double Battles format as stated in the official Japanese Pokémon Global Link website, although the English site incorrectly states that it will use Single Battles.
Only Pokémon that have five weaknesses or more and are in the National Pokédex can be used. Mythical Pokémon, many Legendary Pokémon and Ash-Greninja cannot be used. Pokémon transferred by Poké Transporter are allowed in the competition. Pokémon can only hold Weakness Policy or any Berries that lessen the damage taken from supereffective attacks such as an Occa Berry. A player’s Battle Team cannot hold duplicate items. All players that participate in at least three battles will receive Ampharosite, Altarianite, Latiosite, and Latiasite Mega Stones.
Players can register between midnight UTC on July 20 and 11:59 p.m. UTC on July 27. The competition will run from midnight UTC on July 28 until 11:59 p.m. UTC on July 30. Players born in 2002 or later will be in the Junior/Senior Division. Players born in 2001 or earlier will be in the Master Division. Junior/Senior Division players can only battle between 6 a.m. and 11 p.m. local time. The rankings will be announced some time in August.
The list of Legendary Pokémon that are ineligible will be announced on Pokémon Global Link’s Weakness Cup web page after the tournament registration begins. Four of the six registered Pokémon will be used in each battle. Every Pokémon will be automatically set to level 50 for this tournament. Each battle will last a maximum of 10 minutes. Players will have 90 seconds to pick the four Pokémon they will use for each battle, and 45 seconds to decide whether to switch Pokémon or use an attack each turn. Players can battle 15 times a day for a maximum of 45 battles.