I recently obtained omega ruby from my friend and I cannot trade shiny beldum acroos to another game, please help.
I'm guessing this is from Omega Ruby to XY
The event Beldum is recieved holding a Metagrossite.
Mega Metagross does not exist in XY and therfore disallows the player to trade it across
This is because it is an event Pokemon, and event Pokemon (as well as some other special Pokemon like Cosplay Pikachu and Black/White Kyurem) can't be traded over the internet.