Gengetsu, Mangetsu, Shisui AND scarlet blaze. So the 1st passive of the 4th line of sb has the same exact issue of water enhancement in that team and shisui do not boost gengetsu (that's why mei and not shisui).

Jinpachi was better than Mangetsu at the time garv talked about, not only because gives a 2nd standard attack granted every round (Mangetsu doesn't do it in round 2) but also because his mystery pop all the dodges so gengetsu is sure to hit twice the target.

Water main with shark bomb is better in general in that team because is a blitz team so she grants not only the highest boost to gengetsu but also an heavy additional and unexpected round 2/3 hit that may also let you use in round 2 both her and mei, something quite huge in arena.

But obviously as any blitz team is a all or nothing. If something doesn't go as expected you are sure to lose.

The idea basically was: round 1 gengetsu reduces cd and the combo his mystery triggers kill or make unable to do anything the enemy move 1 hero in round 1.

In round 2 shark bomb + jinpachi + eventually mei (if the clone dies or if you stole enough chakra) wiped out the rest.

P.S. Beware that with a bit of luck, if Gengetsu is in front of naruto, and you have mei barrier up, this team still works also against common six paths meta. Naruto is not able to endure the whole combo triggered by Gengetsu + two standards + mystery even if is shielded by bee + earth main passive. It will be able to only if earth main selects him with his chakra wall.

Yes it does but if gengetsu is not selected by it it doesn't do it.

With mei in the place of shisui works, but still the boost granted by it goes to ninjutsu only while the boost granted by water main goes to tai too.

Try gengetsu mangetsu/jinpachi mei fire main, should work fine.