If you’re one of the Pokémon Sun and Moon players who received an Audinite and a Medichamite recently via password distribution, and you plan on battling in the current Rating Battle season, you’re going to have to leave those Mega Stones in your Bag. This is because they won’t be eligible for competition until Rating Battle Season 4 begins on May 16, 2017, at 00:00 UTC, according to The Pokémon Company.
Source: Pokémon Global Link
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