I think I've seen one in a great ball on there.
I know I was hesitent about using pkm files on smogon long before I'd ever heard of pokecheck, but TheMantyke is as reliable a source as you can get.
I just checked and I have a Jolly Lucario, EVed, with OT "M3" ID 09760 in that ball that I got from smogon. All of my DW Adamant ones have other balls. L0P-RS has a luxury ball Lucario on pokecheck, and I *THINK* that's a legit OT with no known hacks (i337 hacked that one G3 pokemon, and he's heavy on Pokecheck since being banned here... so you have to be careful.)
Remember, though, Lucario is an event... so it might be hard to get one in the right ball. Good luck!