you don't understand, Zed is nowhere near OP. Look up for statistics and majority of the people including me, thinks Zed is a little UP. Zed can't farm now until mid game.
+ Zed play difficulty is max i believe and his style is basically high risk high reward. So I think riot just killed one of the most balanced champs imo. RIP Zed
Diana, i can't say much because I've never played her. I can just imagine Mega's sad face now