I have never defeated those phenomenal pokemon. Seriously the stats on those things are out-of-this-world! I tried once before to defeat one, not to recruit, just to defeat. I recall using jusy my Darkrai I made it attack from in a wall so they couldn't attack me, but I easily lost my hunger even after eating several BIG apples! Plus my PP ran out really quickly actually; quite faster than normal. :\
When I died I was like nooo so close! I was certain I was going to get my revenge on those things.. D: