One of the most fun decks I've played on PTCGLive, currently sit at a 10 win streak. Onix hits like a truck and Steelix can clean up after you've Roxied a couple of times. Get ready for some fast fun games!
Replace any of the other 4 Retreat Cost Pokemon with your favorites, as long as they aren't GXs (Roxie fodder) or basics (so you don't start them).
Enjoy!