Can say that at the current setup you mention for 3.0 with Mei, AO Sage Naruto and Water Main @ level 83 with 39k power, its not possible.

Initiated adjvantage Killed by two mysteries in a row and the team has nothing to attack with until round 2 but they strike first.

I used Will of D.'s line up for that one

https://www.youtube.com/watch?v=Af9jdqmG3Gc

Mei, theoretically, is a free ninja, but requires some luck to be pulled, like danzo or any other kage rares. About how to deal with this exam, bring a super armor ninja and put it in front of sage naruto, gaara for example, and keep jikogudo under chaos. Gaara, iruka, sage naruto lineup for example would work imho with 32322, dog talents.

For example:

sage naruto iruka x

azure fang gaara x

X x x

Round1: You let jiraya kill naruto clone, naruto hits gaara, your naruto summons again the clone and your main heals gaara.

round2: you interrupt jiraya or naruto, depending on who moves first with iruka mystery and you start with naruto a combo on jigokudo to chaos it and to spread poison, or to bd if bd have dance of impetus, i don't remember what mystery have, and you heal if needed.