Full AP Ekko needs to be toned down
I don't think this requires massive overhaul, in fact I'd go as far as saying his damage and stickiness is reasonable. What feels unreasonable is how tanky he is without defensive items between his base stats, shield and ult. I think these are the best areas to start. Ekko blowing up my carry by jumping in without assistance should cost him his life, not just his ults cool down. That wasn't suppose to be his function anyway.