Sage naruto fully skillbroken is one of the few ways to make viable a water main shark bomb team that does not rely on neurotoxin.

Example of the team:

Kushina normal Water main x

X kisame samehada x

X sage naruto x

Talents: 22443, summon: rhino

An op team with him?

Wind main edo hashirama x

Wb asuma sage naruto x

X x x

Talents: 32344, summon: rhino. Summon mystery: giant katsuyu.

Required breaks/trials: senjutsu's debuff removal on naruto, konoha's debuff removal on asuma, interruption on chase on asuma.

A team that relies on his selfstacking?

Edo hashirama minato edo tensei x

Wind main sage naruto x

X x x

Talents: 32334, summon: dog of hell, summon mystery: pakkun

I said viable, not op.

Anyways the kushina that's there is the normal kushina, not habanero one.

The idea of the team is that you do not use kisame samehada round 1 (but generally shark bomb, since kushina clone that dies give you 60 chakra) unless strictly required but you eventually use it in round 2 or 3 exactly to interrupt the enemy move 2/3/4.

Depending on what team you face in round 2 you may even start with naruto mystery and then make follow shark bomb (overall if you used shark bomb round 1) eventually using kushina mystery on main or naruto after the enemy moved.

Once you are in round 3 water main has 90% buff to ninjutsu almost granted and 75% granted. If something on the other side, besides move 1, is still alive means the difference in power is wide enough is normal to lose.

The point is if you want him to be a support or a big damage dealer.

The path with the selfstacking passive is for the 2nd kind of team.

I placed minato in move 1 in the team i suggested for the damage dealer side just because he can interrupt but you may freely swap them if you are confident in your initiative.

About the team i said for the support side, is true that not always asuma works on naruto but does it really matter?

if doesn't remove debuffs on naruto he does it on main and then you use dance of impetus or on hashirama and then he will heal, unless you used wrongly his mystery (you basically usr his mystery only if you are granted to interrupt the enemy, you actually start the round with naruto and eventually you use hashirama after to interrupt who could move before naruto and if your hashirama is slower you just don't use his mystery until the enemy move 1 moved), so doesn't matter much.

You will be surprised by how big chakra coordination healings are on that kind of team.

P.S. The loss is actually up to 28%.