This is at the end of the fourth level. The first in UK.
This achievement will come shortly after this one:
You will only have to make a battle with your dragon in between. Protect the hologram tower and use it to refill your energy.
Other than that just follow your approach in the previous fights. Use X and Y to make combos and use the special cards (d-pad left and right) once they are filled. You can use B to shoot some fireball, but the enemy is not bad at evading, so I only used it in fairly short distances.
Achievement unlocks once you are back in your headquarter.