Your Win Condition
Take short trades with grasp and poke him down.Beat him in the 1v1, get freezes and deny him resources
General Strategy
Avoid parrying his q as it will still heal him if he hits the sweet spot. Darius can pull you out of your q which will put it on a long cooldown.Darius is immobile and vulnerable to ganks.
Trading Patterns
Look to q him with grasp procs especially with vitals.Do not trade autos with him he can just ghost you down.Wait until your bleed stacks go away before trading again.
Wave Management
Look to slow push the first and second waves and fast push the third wave then either cheater recall, get vision, or rotate.If you give push to Darius, you can harass Darius when he attempts to build the slow push but respect his lvl 1 all in and subsequent lvl 2 advantage.If the wave is pushing towards you, then you must poke Darius enough so that he cannot all in you and freeze when the wave bounces.
Their Win Condition
Darius will try to force an all-in with ghost when the wave is on his side.If you q in without a vital proc when the wave is on his side then he can ghost on you.