As long as his windwall exists, he will always be unfun to play against for the 99%. lets see 18 second cooldown? that negates (without having to actually aim it mind you) the enemies big cooldowns that happen to be coded as projectile. Ex, Braum, whose ult erupts the GROUND right? is completely negated by an 18 second point and click for the TEAM. Put in perspective a 60-130 second skill is negated by 18 x 5 (the team).
I personally don't care about his passive shield who I have seen negate an ezreal ult when he was within death range. I don't care about his double crit chance. I don't care about his free armor pen. I don't care about his tornado that spans the length of the screen. I dont care about his tornado making your q pbaoe, negating even having to land the q "skill shot". I don't care about his ulting on the backs of anyone eles random knock up that spans the length of the screen. I don't care about his mobility. I don't care about using your own minions against you. I can go on and on.
The problem is very simply his windwall. You don't aim it, just drop it and behold "Im so skilled! haha you cant hit me or my TEAM with anything!! and muahaha now that you have no cd's you will die! HASAGI!" You remove or rework this and the hate for yas will drop in my humble opinion, and the 50% ban rate will drop as would his win rate. No other champ can literally feed, lose lane and still kill your whole team because of innate power, and no other champs can negate a good portion of complete champion kits on an 18 second cd. to be honest? this is beyond ultimate power, that shouldn't be on his W. Its like old TF, like beta TF, they changed his ult from his w to his r because gee, it wasn't very smart to give a champ a 30-40 second map blink, lol
If there is another champ like this by all means, let me know, I could be wrong.