Zed, Talon, and Fizz are a problem. Here's why.

I've had this happen to me so many times, it has made me take many hiatus's from mid lane when it's easily my best role. Say level six just happened. I am underneath my turret, but the wave hasn't pushed all the way. It's pushed halfway to mine. I can be Orianna, Morgana, Karthus, Kassadin, Anybody. Me being full hp, they shouldn't be able to all in me when we are both full hp full mana, and escape. I've seen it with Zed many times, Talon sometimes, But especially with Fizz. He can max range ult and I'm not prepared to try to dodge skillshots at the moment because I'm just sitting there trying to CS, and he is a Fizz in lane, so I don't expect any skillshots that need to be dodged. So I'll get hit by a fizz ult, and he can combo me to death under my own turret. He can use E to jump over any cc, and can use q to catch up to me. His damage that low of a level is way too high to be able to just do that.

Tldr; Assassins in the mid lane should have to wait for an actual opening to go in and kill their laner besides just having their ult up.