If you just want a Magearna, provided you've beaten the Elite Four, its QR code from Sun/Moon still works to make it available. This Magearna can be Synchronized 100% of the time to suit your needs. (and save some grief if SR'ing for a good HP type like Fire) No such luck with Marshadow, unfortunately.Anyone have a Magearna or Marshadow up for trade?
And what do u want in return?