MixedZekromLol?
I believe that's what people like to use on Genesect. You weren't using Synchronize to manipulate that?
Does that work on ones like Mewtwo in X/Y? Because I haven't gotten it to trigger, but I haven't tried in a while.
EDIT: Actually, just checked in on my White version a month or two back, and the Zekrom I got in that was Adamant with a 30 or 31 in HP- don't remember off the top of my head. Haven't transferred him yet. Want to at least grab Landorus before I do that.