I can't believe i'm saying this, but I believe Kitty Pride has finally dethroned Quake and Ghost.
She has like 2 counters, prowess removal and AAR.
I can name 2 champions that have prowess removal off the top of my head.
War Machine and Nimrod.
AAR Also messes with Quake and Ghost.
Quake has for counters (other than AAR), Evade, and passive powergain, which are FAR more common than prowess removal.
Ghost has Armor Breaks and Miss Counters, which are both FAR more common than prowess removal as well.
The one thing you would think would counter her, which would be a miss counter, actually highly benefits her making her be able to loop SP3s non-stop with no damage taken.
If you learn to play her properly with Tigra, you can literally get your 3 prowess, and just phase intercept into a 2 combo, back off and repeat. If duped, you will be taking 0 damage from any sources, and I already covered if they have a miss counter.
Kitty's counters will be far more common in the future because of how OP she is, and we might even see some new work around counters for her, but as of now, I believe we have finally seen Ghost and Quake dethroned. Kitty can simply take more content.