Fizz needs work

I'm not complaining about his damage output, kit, or scaling. Although he does scale ridiculously well, I understand that e is an assassin so that is his job, do ridiculous amounts of damage to the squishies behind enemy lines. My problem with him is his low-risk, high-reward style of play. This is what makes him overpowered in my opinion. What I mean by this is that he can jump into a team fight, kill multiple enemies, and escape nearly if not totally untouched. A typical Fizz scenario in mid-late game: Fizz ults an enemy in the middle of the enemy team during a teamfight. The ult goes off, dealing at least half of the adc's, mid's, and usually support's health in damage. The tanks (assuming the jg and top are building tanky) lose about a third of their health. Fizz then uses his W and usually kills off the adc/mid. The enemy team tries to hit him with a Dark Binding/Aqua prison/ dredge line/ etc. but Fizz uses E to evade all the attacks while his teammates are doing damage this whole time as the enemies target Fizz. He hops to safety and dashes away with his Q to ensure that absolutely nobody can even touch him. On the chance that the tankier enemies survived the burst and chase after him, maybe even hitting him a couple of times, Fizz just zhonyas as his team gets there, uses his E again on the enemies, and dashes away again before the dying enemies can do anything. And just like that, there's an ace. I think his E should be changed to where he doesn't take damage but can still be cc'd. That would make it to where a Fizz can't just initiate a teamfight and come out unscathed. It would add some actual risk to playing him. It also wouldn't hurt to nerf his W because frankly, that stacking damage from his passive and active on the ability is ridiculous.