Fizz Is Impossible To Punish, Especially With How Weak Turrets Are
At this point it is literally impossible to mess up with 
The 1st one he just walked into turret and kills Trundle and E's out, pretty typical for a Fizz.
The 2nd one is just one big fuck you. He's not full health and Q's into a turret, gets ulted under turret by
and then gets hit by every one of her abilites, after the stun from Sej's ult wears off he doesn't use E to escape, he uses E to kill my adc under turret and then Q's out. Let me reiterate that. He dives a turret at 3/4 hp and gets ulted by Sej, and survives.
The 3rd one is infuriating. Fizz is chasing trundle and tries using his E to kill him, Trundle flashes at the very last second into an ally turret, Fizz continues to chase him by just walking into the turret, and then Trundle blocks Fizz's path with Ice Pillar. Fizz missed his E and got trapped in turret by Trundle, so what does he do. He just uses E again. Forget punishing him, its not even possible to outplay him when he fucks up.
Fizz can not be punished even when making the most retarded of plays imaginable. He can literally hard core fuck up and get stunned under a turret and not die.
The worst part about this is that a few months ago Fizz was ban worthy, but now I wouldn't dare waste my ban on Fizz, now there are about 20 champions even more unbalanced than he is, and banning them takes priority over banning Fizz.
TL;DR If you need someone to tank a turret just get glass cannon Fizz to do it, his armor is made out of my salt.
EDIT To everyone saying I messed up my combo in the 2nd one, I didn't. Sej's ult cc duration increases with ranks 1.25/1.5/1.75, It was a rank 1 Sej ult so it only stunned him for 1.25 seconds and you can see from watching the video that 1 second passes between my ult and using Q on him. His E is instant, he invulnerable from the moment he presses it, if I had waited .25 seconds until the ult stun wore off my Q would have went through him.
To everyone saying my post is invalid because Fizz was extremely fed, since when do AP items help you tank turrets?
To everyone saying Trundle should have sidestepped, how do you sidestep a targeted dash?
Here are Fizz's mistakes or what should be mistakes for those who asked. 1 Q'ing into turret aggro. 2 Not using E to escape turret. You can say it was a good play by Fizz using his Q to get out after he used E, but I argue that his E should not break the turret targeting if he didn't exit turret range. 3 Missing his E on Trundle, he got outplayed by Trundle. 4 Walking through turret aggro and getting trapped in turret by Trundle, he got outplayed by Trundle. If you watch the video and count the seconds he used E literally 4 seconds after Trundle flashed to dodge it, even with max cdr the cooldown should never be so low on an incredibly powerful ability.

This item shouldn't be in the game.
Nor should Fizz E IMO.
isn't an assassin?!? someone should tell riot....
