all assassins are bad in the late game. That's the hardest part of the game for them.
This includes even Katarina.
The reason late game is hard for assassins in general is because the enemy team is grouped and you cannot survive focus fire for 5 enemy membrs and also, the enemy team will have heals, shields and exhausts available for them to shut down your damage.
Zed also fucks up your team's damage composition because there's very few AP champions viable in the jungle (most are AD) and a medium amount of top APs.
With Zed, you need to win the early game. And as an assassin, you have the tools to win your lane starting with level 2 or at worst, level 3.
I also remember when Zed was strong and he had like 80% ban ratio because he could easily kill adcs and pealing supports such as janna and lulu weren't meta.
The thing with AP junglers is. Here's the list of AP junglers:
http://na.op.gg/champion/statistics
sort by junglers.
Amumu - tank
Cho - tank
Diana - good, ap damage.
Mundo - tank
Elise - good ap damage early on, scales awful into late game, so, she's middle of the road, you will stick lack ap damage later into the game and the enemy tank can just build AD, but you got AP early on, so, that's a good thing??
Eve - gona be good post rework, right now, she's not really an AP champ
Fiddle - sucks
Gragas- tank
Ivern - tank support
Nunu - tank
Ramus - tank
Rumble - good ap damage source
Sejuani - tank
So, out of those. The only ones that can count as AP damage source is:
Diana, Fiddle (which sucks big time), Elise (but she falls off badly), Rumble and that's it. Eve will join the pool post rework. And I figure out, then playing AD mids will be easier as AP Eve is going to be quite popular (unless banned).
As for top laners. You got:
Akali - good AP damage, but not good as an AP damage source against tanks. Will still force any top lane 'tank' to build ap otherwise she will stop lane.
Ekko - no idea
Fizz - no idea
Gragas - tank
Heimer - good
Khartus - good
Kayle - good
Kennen - usually goes ad
Lissandra - good
Malzahar - good
Malphite - tank
Maokai - tank
Mordekaiser - no idea
Rumble - good
Ryze - good
Singed - good
Swain - good
Teemo - good
Vlad - good
So, in this list we have.
Akali, Heimer, Khartus, Kayle, Lissandra, Malzahar, Ryze, Swain, Singed, Teemo and Vlad.
And potentially Ekko, Fozz, Mordekaiser.
Now, real question.
How often do you see this picks?
Such as: Diana, Fiddle or Rumble in the jungle?
Or the top laners that I've mentioned?
Its quite rare, that's why people expect usually mid to play AD.
I'm an akali/katarina player. And can take akali top without an issue. Hence, this problem is not for me. But, a lot of players do not like AD mids for this reason, because your comp will usually end up full AD and the enemy tank can build very much anti AD and win more easily.
Meanwhile, if nobody plays tanks................ then, it doesn't really matter lool.
But still. How can you claim Zed is good in the late game?
Especially if you played Zed from gold to dia?
He still is an assassin and falls under the assassins's short comings.
Even the reset queen Katarina is week in the late game.
Assassins's power spike is usually from lv 2-3 (or 6 specifically in the cases like diana where you only get your gap closer at 6) and in the mid game. Then they start to fall off.
