Formation:

X-Gaara-Iruka

Main-Sage Naruto-X

X-X-X

Skills: 4-4-3-4-1, Snake

BP: 91414

Ghost Kill Lvl 5

I had to place Naruto last, so that his clone doesn't get iruka's shield, so he dies faster in the second round.

First round: Main shield and Gaara Barrier, target 1st hokage edo

Second round: iruka skill before 1st hokage can do mystery. Then hope both fire main clone and Naruto clone die before chakra drain chase hits. use Naruto skill on 1st hokage.

third round: use gaara skill on 5th hokage, this should kill 1st hokage too if still alive.

remaining rounds:, kill 5th, then gaara, then 4th, then naurto with any skills you c*e :)

I only beat it once, so I might have gotten really lucky with RNG, but here it is.