If Ahri can land an E, she will certainly do some decent chunks of damage to her.
Near, if not, instant crowd control is always good for stopping a hyper mobility champion.
Once again, instant crowd control. Fiddlesticks also has some sustain to go with it as well.
Fizz has been known for having hard to dodge burst, which is LeBlanc's usual bane. If she can't dodge it, its gonna mess her up.
Back to instant crowd control lane is the real LeBlanc hard counter. Galio just has to R and throw a Q or two and she is or is near death. His passive also promotes getting magic resist while also getting stronger offensively.
W or R, instant crowd control. Screw you and your blinks LeBlanc.
Did I mention the benefits of instant crowd control and hard to dodge damage yet?
One of the few "all it takes is one" champions. All Morgana really has to land is one Q and LeBlanc will be out of lane or be taking some serious damage.
INSTANT CROWD CONTROL!
I TO THE C TO THE C! WHAT DOES IT SPELL? INSTANT CROWD CONTROL!
Once Veigar can get enough AP, LeBlanc isn't even a thing as long as she isn't extremely fed. Even then, Veigar's R scales off of her AP as well, making her still take a lot of damage that can't quite be dodged.
Super burst and mobile assassin vs super burst and mobile assassin. Who will win? Pretty close match-up, but Zed has overall the upper hand due to him having Energy and in my opinion, stronger ultimate since it makes him cast his spells 1.2/1.35/1.5 times plus an extra 0.5 or so times for every shadow spell he hits.