To get the unlimited turns and get the achievement, you need the following cards
Tablet of Times Dawn, Hedron Link Device, Rocket Courier and Reclamax. To make this achievement easier, just have the original card game with the Return of the Fallen expansion enabled.
Once you have all 4 cards, banish the Tablet, next use Reclamax to pull the Tablet out of the void and put it directly into play, then put back Reclamax into play. Rinse and repeat.
You can view my video to help you out, you can go to the 40 minute mark to view the unlimited turns.
Thanks
Killarpong