Does LeBlanc need a rework in the likes of Karma and Sion?
So honestly, do you think she needs one?
She has always been too strong or too weak, her kit is extremely hard to balance because it rewards her for completely destroying someone in like 2 seconds and blinking out of trouble barely touched. She has an easy time getting away and an easy time bursting people and then leaving. Yes, you can try and cc her, but most of the time it's either too late, or she's at least chunked you down, or she knows you're going to cc her and she just blinked back. Her play-style is just too frustrating, even when she is weak because she's also so damn hard to catch.
Thematically, she doesn't really fit the role of a deceiver because the only really deceiving thing about her kit is her passive and that's about it. (2 if you count her w, but it's honestly not that deceiving because you already know she has an easy get away plan if things go to shit.)
Visually though she's fine imo. She could be changed a bit, but I assume you can kind of say that for any older champion.
As a disclaimer, I actually really like playing LeBlanc because she's really fun and a different type of champion, but as someone who has played against her several times, she's just such a pain the ass.
TL;DR: She's a pain the ass when played well, which honestly isn't that hard to do tbh.