You can now obtain the first mythical Pokemon exclusive to Sun & Moon : Magearna. It is an artificial Pokemon created by a scientist 500 years in the past, and has a mechanical body that resembles a Pokeball. It has a new and exclusive ability, called Soul-Heart, which raises its special attack stat whenever another Pokemon in the area faints.
You can get Magearna for yourself by heading over to the official Pokemon Sun & Moon website. Scan the QR code on this page using the in-game scanner function to add Magearna to your Pokedex. Then, all you need to do is head to the antique shop in the Hau’oli City mall and speak to the deliveryman. He’ll hand over the Pokemon, which you can add to your party right away or send to a box for safekeeping.
The only catch is that you need to beat the main story of Pokemon Sun & Moon before you can obtain Magearna. The event is not bound to a particular time period, so there’s no rush to finish. If nothing else, Magearna should make a fine addition to your lineup as you challenge the Battle Tree on Poni Island!
Source: Pokemon.com