Mystery gift in Pokemon emerald through vba?
First download the latest emulator of vba (1.8)
Then go to options>link and make settings and connect then open another vba and connect it. They will be connected and then you can send mystery gift via another vba
During a Nintendo event Nintendo gives out mystery gifts if you bring your Pokemon emerald to the event with a wireless adapter and Nintendo is giving out a gift emerald can receive you can go to a wonder spot and choose mystery gift on your emerald to receive the special gift. But all Nintendo events for emerald have long since passed.