Who wins: Hard counter — you

Darius is stronger in the first levels — shove and deny farm.

Twitch escapes faster than you — take farm and towers instead of running.

Twitch deals physical damage — Death's Dance as your 2nd or 3rd item.

Twitch is squishy — wait for every ability, go in once. No half-combo trades.

You out-trade Twitch; the only danger is their jungler — ward before pressing.

Twitch gets far more dangerous with the ultimate — dial back after level 5.