Unfortunately, I didn't realize you could now purchase uncommon cards through the mastery orbs, and accidentally bought one, which means I can't complete the set, as you can't get extra orbs from playing, although you can get extra uncommons.

Could the extra uncommons on the mastery orb list be extra orbs (incase you mess it up like I did, you could still get some more orbs.

How did I accidentally buy an uncommon? After playing for a month or so, I don't spend them as soon as I get them, and so had a large number of spend. Actually had enough to purchase everything I thought, so I was mass clicking through and didn't realize that feature had been added.

Perhaps adding a feature that is a purchase all, if you have enough orbs for all of it?