Greninja was by far the most hurt character coming from 1.0.0. Rosalina's the only character that came close to his nerf amounts, and even then she had further to fall/wasn't nerfed as severely/ended up finding secret buffs from some of her nerfs (reduced nair kb allowed it to combo into dash attack, for example).
I find it confusing because, like @
elusiveTranscendent
said, he wasn't even #1 prepatch anyway. And then characters like Diddy actually got
buffed...
But eh, yeah, a decent chunk of what Greninja got in terms of nerfs was deserved, and there were some buffs sprinkled in too (dsmash, shadow sneak). 1.0.0 usmash was legit one of the dumbest things ever and nobody sane could deny it.