Graves

Graves is a huge thresh because of his E (Dash) increases his armor making it hard to one shot. Really easy to kite Rhaast and you should avoid fighting him at all in the early game. Later in the game you can one shot him with Shadow as long as he's E is not stacked.

Master Yi

Yi is extremely annoying and great counter. He out damages you early game, out scales Shadow and DESTROYS Rhaast everytime. He's W (Meditate) allows him to counter Kayn R or One shot. Always play on the opposite side of the map and get lanes ahead. If you don't have CC on your team to lock him down, dodge.

Vi

The biggest threat here is her early game power, early gank potential and her invading you! If you're able to avoid her until you get form you should be okay.

Elise

Her stun, E (Cocoon) is the biggest threat, dodging might give you a chance against her early, be very careful. Later on though, with form as long as she didn't get fed, you'll be fine with either form, dodge E with Q or R. She might buy a Zhonya's which will make it harder to kill her, but you'll still be able to chunk her. Sidenote, her early game snowball potential is huge, she can destroy all your lanes if you don't actively work on possible counter ganks, counter jungling and opposite side ganks.

Kha'Zix

Lee Sin

Fiddlesticks

Udyr

Kindred