For anyone that still has trouble with the no hit,try to buy the Gelly Fish item, it gives you a shield to absord damage and not lose the no hit.
Just fill you inventory with these and doing the challenge is easy.
Really? It worked for me earlier...
i'm going to check
Edit: tried it 3 times and it worked, I used 3 Gelly Fish because I got hit a couple times, but since I only got hit once in those turns I didn't get damaged and proceded to the full nelson scene.
Maybe you did it wrong or there is a difference between phone and pc?
I was using phone to test it just now.