Ban him. If that is normals then you will have to deal with it. He will be getting some nerfs. Wait for it. Stay away from ranked cuz all OP champs are running around. All 5 bans will be used for all of those reworked champs.
If you want counterplay, then you need ganks, good positioning, and not a single teammate can die from Darius, or GG team fight. Focus him if he is the threat. Have butt loads of CC. Exhaust can only get you so far. His pull got nerfed. His usual build makes him beefy but not that tanky. He only becomes tanky when he gets 30% missing health back (that will get nerfed). Build some armor because now he only deal physical damage but beware, he will have 25% from his E at lv 13, 6% from his mastery and 30% from BC. Vayne is good against him because she have good self peeling and dashes. Champions that have dashes will be better against him and also AA reliant champs are good against him.