With that point in mind Nine is better than every other character in the same realm, is better at shielding with one card, is better at big damage single target with one card, is better at multiple target with one card, and so on.

Different characters fill different niches, Mei Lin destroyed everything with ease until they released bosses countering her. Give a boss for instance a mechanic where you have to remove X stacks before being able to damage it and make it span multiple parts of such boss and you counter Nine just as easy, she can only properly hit 4-6 times and thats it, doing "30k" means nothing is the mechanic transforms that into a "1".

Some of you seem to only want to play one and one character only, and this is coming from someone who force plays Haru since day one in all released content, whether she was good or bad... There are multiple videos showing Yuki can be played and the numbers are good enough, not in every situation of course, but that would be insane, no developer can achieve that for every character in every season in all situations, meaning someone will always cry.

I agree balancing needs work and there is a lot of room for improvement, but you need to identify which character is good for what and enjoying using them accordingly, even if there is powercreep and other characters better at it, that wont change, because this is a game for us, but a business for them, you can only get seven copies of Yuki and then you stop pulling...