Swain Stupidly Strong

Swain is extremely strong atm his damage is off the charts and has one of the best win rates among top and mid champions he needs some serious damage nerfs primarily on his q and r and the sustain throughout his kit needs to be nerfed because his passive heals combined with is insane. Atm there is no way I can see he is balanced at all but I would love to hear your counter-argument.