Good Morning hope everything's fine.

here i'll let you two formations most known to pass that level it requires a little of luck since Mei need to be defeated at the end of the second round and Sakura need to be controlled in the first round or defeated in the beginning of the second Round also don't bother if Iruka and Neji or Fuu are defeated by Mei in the beginning of the second round. (it would be easier if you show to us the ninjas you have)

To start Neji will need to block the two Mei attacks and Sasuke need to attack Iruka otherwise Neji will need to block all the attacks to don't be defeated before Mei attack in the second round for that u will need lucky, if Neji block both Mei attack then use Neji mystery in Sakura to seal her (Make sure all your higher control runes are on him), if u see she is not being sealed don't matter how much time Neji use his mystery to attack Sasuke that way he will be the focus of the heal and will make him easier to defeat in second round, also before Sasuke Action u will need to use his action (make sure Ao already used his mystery in Iruka before use any line up mystery).

At the Second Round Iruka and Neji are supposed to be killed after Mei attack but if you are lucky Neji can block Mei attack regardless of what happen use the Main mystery in Mei and when u received the chakra use Sasuke Mystery in Mei as well after that is expected to have Mei, Sasuke and Chojuro defeated, after that is just defeat Sakura and Ao.

For this second Formation the order is almost the same u will need luck to Mei get Chaos for attacking Fuu puppet, after that u will receive chakra from Fire Main Passive use Iruka mystery in clone in the front of Sakura letting the way open to Fuu attack her, at the same time use Sasuke mystery to break Mei barrier.

After that in the second round u will need to do the same as i said in the first formation. Also i recommend for the both formations you use Ninja Dog Pakkun Army as summoning mystery it will help to lead extra damage in the second round.

I hope this helps you and if you have any doubts you can check out the WillOFD890 video: https://youtu.be/f0aNiNtDC-c