I am wondering this because it's stats look good and it has a good move pool but the problem is it's catch rate which is as low as some legendarys like Zapdos. But I really want to use it for my omega ruby play threw, so is it worth the wait and effort?
This applies to all games where Metagross is available.
Yes it is worth it, it has a great movepool and great stats it's not a pseudo legendary for nothing.
But I don't think you can get a beldum in oras until you beat the delta episode.