Runaan's should make that Kayle literally have an entire item wasted...
But the rest of the build was good. Kayle is extremely strong because of the way the offensive masteries help hybrid autoattackers (Teemo and Kayle). Her autoattack buff spell (E) procs both of the masteries that increase damage if you cast/auto, so she's basically always got a 6% damage boost from two masteries alone. Also, her Q scales 1:1 so her early game trading potential is quite strong. She walks up and presses Q on you, and you already lose 150+ HP in one spell...
Even with her Q, Kayle's early game is mediocre at best, and if you time an engage when her Q is on cooldown, she is usually pretty susceptible to an all-in aggressive attack (e.g., gank or something like an Ahri charm+ult or Kassadin ult on her face). Playing assassins with a dash against her can shut her down pretty quickly. She's kind of the Jax of the mid lane... if you let her CS or get kills, her snowball is unstoppable. Gragas is an exception to the "assassin" general counter trend. Gragas has a really strong poke AND his all-in potential is really good because of Body Slam. In general, find a mid laner who is comfortable being up close and personal, and Kayle will have a much harder time.