Darius W no animation/ auto delay

i just now finished a game in ranked as Darius, lost miserably but i noticed that after using his W there was no animation and a long delay before the next auto, as though the W took up 2 auto slots, it made it much more difficult to accurately gauge damage and time autos, and overall made the game less fun because i was unable to use my W unless i was sure i wasnt getting in another auto. Also like i said theres no animation for his W which threw me off every time i used it as i was unsure whether my attack went through or not.