The last game OG vs G2 is great example how broken Zed still is.
I had this matchup in my games several times (no I wasn't mid] and Zed always win. Teammates were cursing our Lissandra how can lose that matchup and I was always defending that player explaining Zed is broken and AD itemization is superior to AP atm, that there are no good choices for AP to get vs AD champ, rushing Zhonya is a trap but if you don't its instawin for him etc. etc.
OG vs G2 confirmed this.
1lvl behind Zed wins 1vs1 against fed Lissandra? No way this should be possible.
Zed bad in lategame? Lol not anymore with s6 AD itemization.
Zed has counters? As you saw, not really. There are champions with good abilities against him, but he doesn't rely on ultimate anymore with that brutal damage he can output. And with his new tanky build, he oftens uses ultimate just to gapclose and then target different target.
I will keep banning him, till we get new AP items or he gets nerfed more.