Kayn
Why?
kayn have all what u want why again ?
-blue kayn can do magic damage and burst enemy and have good mobility and u delete walls with your e and get mov speed and u can't get slow u can even go as bruiser item and do damage
-red kayn can heal if u do any damage to enemy like aatrox and your q do max hp damage so more tanks they have to more damage more heal u get and his w have knock up so if in team fight and have yasuo just make sure knock up 3 people and his ult do max hp damage and heal u
but !!!!!! kayn early game so weak so never try 1v1 and make sure u have cs lead