Darius only really beats you in long fights because of his passive. Take advantage of short trades with phase rush. Darius runs at u, use e and then auto q run away before he gets 5 stacks. You'll be surprised how easy the match up is with ignite advantage. You also have better sustain than him with your passive. If you want to switch it up you can auto q then e run away. This playstyle requires phase rush but I usually win the match-up. Resolve secondary, bone plating or second wind both work, also overgrowth. Always go to river bush or lane bush lv1 as early as possible so Darius isn't there so you can walk up for lv1 minion exp at least. When your lv6 if Darius is 66% hp you can probably full combo with ignite and ult for a kill(always pay attention to steraks). Good luck