change ad items or adc's?

so i played my main kat and it was going great i was really fed played vs vayne, tristiana, lux, katarina and kog maw. but they got fed aswell by my team who i think some were new to the game but whatever this vayne had maw of malmortius (which i feel is a bit too powerful) but the point is that eventually i saw this vayne i do my combo perfectly but he did 3 basics where one was his Q tumble and it actually killed me. i used my ult and everything hit him but his magic shield popped from maw and i just died. like there are so many ad items i feel can burst down an ap carry so easily . but mostly maw of malmortius is the most powerful ad item against ap champs and it just totally ruins a 1v1 even if you were fed in early when they get this item they suddenly turn around the fight.