Zed just got nerfed this patch and people here are still bitching about him having "no counterplay" and being "unfair".
As a mage mid player, I find zed to be one the fairest matchups in the game. He is vulnerable to early game harass, weave in autos. His w has a 22 second cooldown at rank 1, which means if he uses it to harass you, you have a lot of time to harass back. Make sure to save your cc for when he jumps on you. Rushing seekers is no big deal because it is a very efficient item. A level 6 serrated dirk zed will at most do 70% of your hp if you are level 6 and purchased seekers, and that is if he hits triple q.