Why is not viable with wind? Kushina, bee sst, wind main works quite well with him.

Yes, because kushina standard attack is like sage naruto one. If you use serpent you are almost sure to deliver it as long as you use high combo standard and high combo chase. At most could happen, if you find a superarmor in front of kushina or an evading ninja that you reach 35 or 50 chakra, but in that case, depending on the situation, you can heal main with kushina mystery or use kushina mystery, if your main is able to move, to start a 0 chakra combo that grants you the missing chakra. Obviously you could lose initiative since 6 tails bomb in this case would be forcefully delayed, but with 6 tails could not be a real issue, at most you would deliver higher damage due to lower hp and then use dance of impetus. You would need to find a team able to cc your team twice per round to find some real issues but they would be also compelled in wasting both of them on your main and still, in round 3, you could have a chance to use an uninterruptable dance of impetus between the two standard attack bee grants to the beast or to kushina and hit again with the bomb.