I tried this challenge a couple of dozen times and was never close to finishing it, having finished the game and maxed out my lightsaber on the way. You can complete the game before you do it, but I would at the very least warn people not to put points into the lightsaber until they've done that first challenge. The first challenge is overwhelmingly difficult if you have fully upgraded your lightsaber. However, PuckJunkie offers alternative advice:
This is because it will provide you with more advanced combos and moves to remember when it comes to your unleashed playthrough. It is probably best to do all the challenges once you have completed the game.
