she is good but people won't even consider using anything that's not outright broken like the current water meta that has spawned multiple cancer teams and for some reason water main meta is always the cheapest to get. In my opinion she is one of those ninjas whose kit sounds good on paper but when it comes to actually using it falls apart.

For me, Kushina is good, and better if she's 3star(Gains Immunity). Her mystery skill is quite good as it has a cancel kinda debuff and the animation of her running towards the enemy and hits like a baseball player with her glorified frying pan of love is really funny XD I currently using her in my extra account together with Minato4thHokage and GaaraKazekage, WindMain Class.. And im rolling in arena smoothly :D

She is actually a good support, I have her as 2 stars and she is wrecking the arena. Her clones are tanky and everytime they die she just keeps spamming it, She has immobile and a unique mystery that interrupts and heals and removes debuffs that only downside is that her mystery's cooldown is 3 rounds.

I like her. I like her a lot more that I know she gets immunity to debuff at 3*

6 tails naruto, kushina, full skillbreaktrough hashirama, both with azure fang and crimson first is currently a whale meta team.

I wonder how many banks do I need to rob to get that lineup...

?

This team would never work in the "whale league", the roshi healers teams will outsustain you, the kumo lightning teams could tear you apart. You could probably do good against the itachi-minato teams... but only if you play well your hashirama.

at 3 stars yes, at 2 stars no, the immunity changes things

If you do not understand how big the impact is of her in bee sst place in that team there is not much i can say to you. Just let you point out that there will be 1/2 more characters to hit on the field every round, that there is a 0 chakra cost interrupting high damage mystery and that there is a sure immobile chase and a 2nd unavoidable standard attack.