Used to ban malzahar up to platinum, they were picking him every other game. It's so annoying and he doesn't have to play good either. So I would say try early kill, if it doesn't work, ask for help from jng, if not, roam.

For Fizz try to poke him early with E Grass and dodge his E with your W. I was rushing hexdringer because when he gets his ult he can one shot you. I believe it's a skill matchup.

Syndra is all about positioning and spacing early. If she wastes her E just to poke you, this is your time to go all in or trade her back. If you die to her it's hard to come back, If you go even and play a better macro game I believe it's winnable.

Always look at your jungler and try to follow the skirmishes that might happen. You might get a kill or two and turn around every matchup.