A new Mystery Gift event has started for Pokémon Sun and Moon! Mega Stones for Houndoom, Steelix, Pidgeot and Heracross (Houndoominite, Steelixite, Pidgeotite and Heracronite respectively).
To download these items, use the code of AZUL from the Mystery Gift option of the main menu of the games. There is no end date as of yet for this giveaway. However, you will have to wait until the next update of the Global Link (16th of May) to be able to use these items in WiFi battles.
Are you eager to get these Mega Stones, or are you waiting on other Mega Evolutions?
Thanks to Fletch for the tip!