Apparently 'all' Assassins are doing bad or subpar right now...This is fixable
They all share a common factor of a delay that's just a bit too long. Talon's W return speed makes it quite easy to dodge. Or how his initial W doesn't slow anymore...can just add a weaker slow on his initial W like it was before.
Fizz HAS to ult if he wants to proc his W burst right after. Otherwise, he has to Q, maybe E for security/waiting for the W bleed to hit 2 seconds, then jump down and W. And you might not even hit them with E.
Kata has to wait for her W to do a loopdeeloop in the air 3 times before she gets her 2nd blade spin. This one is slightly ok, but maybe a tad faster animation.
Leblanc's big damage is behind 1.5s...procs in one E, or a W-wait-Q (and so on with the combos)...it's just clunky, imo. Damage is fine.
Solution: The Lethality treatment. For some of these champs that are real clunky to play, make the delay scale down through leveling up. Or just make delays faster for champs that are close to being a decent rework.
For the assassins that might actually have number or mechanics issues, also easily fixed. Revert Akali W, maybe fix her ult cd..and so on.