Hey so uhm im quite dissapointed you never see Leblanc players anymore.
I was a huge fan of her, but after some changes (nerfs) she lost hard popularity.
She lost waveclear, and i believe her spells were delayed making her less of an assassin.
And i believe the issue lies mostly in point B, the delay, when you fight against her now you have a big window in which you can attack, predict, and plan your move. making the all in less usefull, risky, and potentially resulting in your own death more than before.
This is even worse of an issue in high elo/thehigheryougo.
In order to compensate for her losses, people are now ''forced'' to build gunblade, giving some extra damage and a slow to buy extra time.
However that is a plaster and she has to alter her ''standard build'' to be of more use again.
This is an adaption, not a fix.
She still has 49% winrate, but i believe most of that comes from lower elo where she could be a stomper.
There are simply better, faster, and burstier APmids out there with less risk, and a lower skill-cap.
I hope Riot will give her some love again, i loved playing her, she was one of the true ap assassins.. and fun all around.
a once clear fan-favorite.