I found out how to deal with Zed
I don't know if it works just on Lux,because it;s the only champion I experimented with,but in 3 games where I played vs Zed,I felt absolutely no pressure from him. 1)Get Boneplating - Assuming you only get hit by ShadowE + Shadow Q+ Zed Q,this should be the rune to reduce his poke damage,thus his ult damage too. 2) Get 3 doran rings (or other doran items) so you dont have mana problems and get some health before Zhonya. 3)zhonya. At this point,you are at 0 risk to get killed by him unless 2 other lanes assist him.
Try this out,and let me know some results. Hope it helped!

would be nice if it weren't for the fact he doesnt need Ult to Kill mages, and if your going to make the excuse that armor will stop him his passive deals a lot of damage in its own right which is magic damage plus he builds leathality items like
. that just negates most of the pluses from building it and unless you plan to build
then hour glass is the only armor that mage will build.also you can push him into his tower as a mage to deny him farm but thats suicide for mages since junglers will just camp.Even if you dont feed him kills he just out roams you and gets fed from the other laners who dont meticulously play around one champion from another lane.
just run at him
all in him lvl 2
shove him in and punish if he fights you
Just hit all your buttons
land 1 knockup and delete him
pool his ult
pole his ult
Just all in him whenever you feel like it
Mash Q
ETC
He has a strong outplay kit, but he isnt unstoppable.